Lilly is an original character who first appeared in Telltale Games ' The Walking Dead: Season One . She is the daughter of Larry. and acts as a leader in the group. She is also straight to the point regardless of how people react or feel about what she has to say. However she does have a kinder side to her.
At first glance, Lilly is quick to earn the dislike or disrespect from the group, particularly due to her association with Larry. her father, and her constant take on siding with him. For the better part of the episodes, Lilly assumes the role of the group's de-facto leader, probably out of the reason that nobody wants to take up the responsibility.
As Lilly has military experience (Air Force, specifically), she handles herself pretty well among the men and isn't afraid to speak her mind in order to protect her father and herself. Additionally, she is knowledgeable in survival tactics and firearms, which became a trait for good leadership. She even set up a training regimen for the adults in the group. In general, Lilly is rather bossy and possessive, having the need to control the group in a way that she sees fit. An interesting point to note however, is that when Larry starts acting out in a fit of rage, she is quick to act as a pacifist and attempts to calm him down, to no avail at times. This shows that unlike her father, she does not bear the similar bitterness and resentment that he has for everyone else, although she does have a temper not to be reckoned with.
Lilly also tends to hold grudges. As there is only one point in which Lilly could have developed a dislike towards Carley onscreen. When Carley went against her directions, and then called Kenny boss. Lilly later states that she never trusted her, should she be saved in "A New Day". Other than that, the two rarely interact.
Lilly can also be fearful. In a desperate attempt to be allowed back into the group after killing Doug or Carley. she reveals that Lee Everett was a murderer before the apocalypse. After that, if she is allowed back into the RV, she expresses that she feels afraid about what the group will do with her. She will then steal the RV, hoping to escape any harm that the group may bring to her.
Should Lee try to get in favor with her, the game will reveal a softer side of Lilly that is in fact, a warm, considerate and polite lady who is unsure about her capabilities as the group's leader. Repeated conversations with her will show that Lilly tries to apologize to Lee on behalf of her father, stating that while everything Larry does is ridiculous, it is in the intention of protecting her and affirms her ground on siding with her father. When caught in conflict with Kenny. she reveals that she tried to see things from his point of view as a father and husband, yet finds no reason to support his decision, as it puts everyone else at risk. In fact, she confides Lee at times by asking him if her decision was right as a leader.
Despite having to prioritize her father, between Kenny and herself, she is more interested in overall group's welfare, and thus prioritizes everyone equally whereas Kenny seems to prioritize his family beforehand rather than anyone else.
At the end, Lilly's personality and responses are entirely dependent on how Lee treats her throughout the story. Simply put, if Lee tries to get in favor of her, they will get a glimpse of Lilly's softer side. Vice versa, if they go against her, she will continue to put up a tough persona and fight for what she thinks is best for the group. As of "Starved For Help " onward, Lee's relationship between her and Kenny will be put to a test.
Robins Air Force Base
Lilly, is the daughter of an army man and was stationed at Robins Air Force Base where she held a desk job. She is used to dealing with pushy military men and immediately takes charge in tough situations. During a conversation with the St. John family while waiting for dinner, she reveals that she had seen action during her service. While incredibly strong-willed, she will always submit to her dad, Larry, a grizzled old man with a history of heart problems. 
She is first seen while saving Lee, Clementine. Kenny, Katjaa. and Duck from a walker attack. She takes them into a drug store where her group has set up camp. However, when rescued, her father, Larry, started yelling at Kenny and Lee for putting them in danger and claims that Duck is bitten and needs to be thrown out. Lee then needs to make a decision on whether to side with Kenny or Larry. As the group argues, Larry suddenly has a sudden heart problem, causing him to faint and collapse to the floor. Lilly takes care of him and asks Lee to get pills out of the back part of the pharmacy which is still locked. Later, Lee comes to talk to her and apologizes for what happened earlier, which she somewhat forgives him for. She continues caring for her father while Lee, Carley and Glenn are at the motel. When they get back, Lee attains the keys and they finally go and get the pills. However, when they open the locked pharmacy door, the security alarm goes off, attracting many walkers. They get the pills, treat Larry, and figure out a plan to escape. Lilly, Larry, and Glenn protect Kenny and his family while they get the truck, while Lee, Doug. and Carley hold down the shop. After they get the truck, Lilly sends her dad back to get everyone else. However, he punches Lee in the face in an attempt to get him devoured, but Kenny arrives and saves Lee. Later that day, they camp at the motel where Lilly talks to Lee and Kenny on how she thinks they will be okay at the motel, when suddenly the power shuts off.
During the three month gap between "A New Day" and this episode, Lilly, Lee, and presumably the other survivors trained in the use of firearms in Lilly's "intensive training". After Lee, Kenny, and Mark arrive with Ben and the wounded David/Travis, Lilly will then yell at Lee and Kenny for bringing them here. During the argument, Lilly will force Lee to hand out four pieces of food to the starving individuals. After this task is complete she will tell you, with a soft tone of voice, that it's not easy doing what she does. Lee tells her he doesn't envy her.
If given a piece of food she will reject it at first (depending on what the player said during the previous argument), but accept it without much force. She will comment that it doesn't change anything after. However, if you chose to side with Lilly when she and Kenny were arguing, she will gladly accept the piece of food that you give her.
Lilly is then then seen at the St. John's Dairy Farm, along with the rest of the group. When she sees the condition that Mark is in, she is visibly worried. She then complains about the place not being safe for the group and that they should take their food to go.
After Lee and Danny return from Jolene's Camp, Lilly is seen arguing with Kenny for reasons unknown. For most of the episode after that, she is shown standing at the gazebo with her father, Larry. If the player chooses to speak to Lilly, she will reveal that her and Kenny were arguing because Kenny found a locked door and wants to find out what's behind it. Lilly will also reveal a little about Larry's past, telling Lee of the loss of her mother, and how that caused Larry to act so violent.
After Lee opens the door in the barn, Lilly is shown at the dinner table with everyone else. When Lee returns from upstairs and
informs the group that they are eating people, Lilly does not believe Lee at first. But once Brenda St. John confirms that this is true, Lilly looks at her in disbelief. Lee also has the option of telling Lilly to grab a knife, in which she grabs a table knife and stands up, before being held at gun point by Andrew St. John. She then demands the St. John's to let her and the group go before Lee is knocked out.
After Lee wakes up, Lilly, along with Larry, Kenny, and Clementine are trapped in a meat locker. Lilly is seen throwing up in one corner, due to her consuming the human meat. She also desperately tries to get Larry to calm down, but to no avail.
When Larry has a heart attack in the meat locker, Kenny believes that Larry is dead and will return as a walker. Lee must choose who to side with between aiding Kenny and kill Larry with a salt lick or aid Lilly and save her father.
If Lee chooses to help Lilly, he will run up to Larry's body and attempt to help. He asks Lilly to check for Larry's vitals and begins to perform CPR on Larry. Kenny, however, thinks that Larry is gone and is a risk of becoming a walker. He will kill Larry by dropping the salt lick block while Lee is trying to save Larry. Lilly and Lee's relationship becomes stronger, however, Lee's relationship with Kenny takes quite a downfall, as Kenny felt left alone with a tough and unpopular decision.
Shortly thereafter, Lee gets into a confrontation with Danny St. John inside the barn. After Lee is momentarily dazed and Kenny fails to assist, Lilly saves Lee by attacking Danny and pushing him into a bear trap. Later, when Andrew is fighting with Lee during the storm, both Clementine and Lilly will stand by the barn watching as Andrew attempts to force Lee's head into the electric fence. Since you attempted to resuscitate her father, instead of aiding Kenny, she will shoot at Andrew, freeing Lee from his grip and showing a sign of care for Lee.
If Lee chooses to help Kenny kill Larry believing that there is a risk, he aids Kenny in crushing Larry with the salt lick block by pulling Lilly off of her Dad and holding her back. This decision, however, both enrages and upsets Lilly since she claims her father was still alive and causes her relationship with Lee to deteriorate. However, Kenny believes they both made the right decision.
While Andrew is fighting with Lee during the storm, both Clementine and Lilly will stand by the barn watching as Andrew attempts to force Lee's head into the electric fence. Since you tried to help out Kenny instead of her, she will just watch, with no attempt to try and shoot Andrew, despite Lee's cry for help.
If you make no choice, Kenny will push Lee out of the way and tell him he's useless. He'll then grab a salt lick and drop it on Larry's head. This however, will improve your relationship with Lilly.
After the group escapes the St. John's Dairy Farm, the group hears a car parked with doors open. After Kenny and Katjaa see all the food in the trunk, Lilly sides against taking the food. Even if Lee doesn't take the food, Lilly will still help take the food.
After Kenny and Lee return from the Pharmacy, she is either content or enraged with the amount of supplies scavenged. When Kenny suggests leaving in the RV, she scolds him (and Lee, depending if he helped to kill Larry) about how she trusts them. Kenny insists on his plan, and she becomes enraged once again, mentioning stolen supplies. After everyone leaves, Lee comes back to ask about what she meant by "stolen supplies", and she states that someone has been stealing them. She asks Lee to look around for clues. With the help of Duck, Lee finds the medical supplies that were hidden outside, she then realizes someone is selling them out, and takes it very personally, believing it to be a crime bordering on indirect murder, and asks Lee to help her round up the group so the traitor can be exposed.
But before that can happen, she looks outside and finds the Save-Lots Bandits holding the group hostage. She grabs a rifle, ordering Lee to distract the bandits, and jumps outside her window. Lee's distraction works, and she takes the bandits by surprise, showing great skill at sniping the bandit leader and several others, as Lee gets everyone on the RV. When walkers arrive, she barely manages to enter the RV, knowing the Motel is lost. With the motel gone, she loses it and begins to question who the traitor is. She believes it is either Ben or Carley (Determinant). When the RV runs into a walker in the road, and they have to pull over for an emergency stop, the confrontation comes to a head, as she tries pressuring Ben and Carley (Determinant) into pointing fingers at each other, threatening to leave one of them behind.
While the argument gets heated, Carley insults Lilly, telling her that she is being paranoid and is acting like a scared little girl. When Carley turns her back on her, Lilly grabs her pistol and shoots Carley in her cheek, killing her in the heat of passion and then justifying her action by stating that she must have been the traitor, even though she herself didn't seem entirely convinced.
While the argument gets heated, she grabs her pistol and points it at Ben, thinking he is the traitor until Doug pulls him out of the way and is accidentally shot in the back of the head. Lilly shows great regret after killing Doug.
Lee pushes her up against the RV after he demands that she drops her weapon. She does so and says she was just trying to protect the group. Lee is confronted with the decision of leaving her behind, or allowing her to stay with the group in order to pass judgment on her later.
If you choose to leave her behind, she reveals Lee's criminal past to the group. However this changes nothing and she watches as you pull away in Kenny's RV. A walker approaches her and she begins to run. Later, in "No Time Left", the Stranger will criticize you for doing so. (Determinant)
Taking Lilly with you (Unknown)
If you allow her to stay with the group, she still reveals Lee's criminal past to the group. Lilly is handcuffed to the seat, but slips away and steals the RV when it's parked near the train. Lilly offers Lee the chance to join her when he goes inside the RV to get a pencil; Lee can either refuse or accept. If Lee refuses, Lilly will force him out of the RV and drive off, and if he accepts she will tell Lee to get Clementine but instead, tricks him and steals the RV. Kenny comments that she isn't very likely to be able to drive more than 30 miles, as the RV's radiator is worn out and close to overheating.
No Choice (Unknown)
Making no choice results in Kenny making the choice for you, which is to leave her behind.
When you talk to the group upon reaching the train, Katjaa and Ben say that they would have left her. (Determinant) Later on, Clementine mentions Lilly and that she gave Clementine some things for her hair that she still keeps.
When the group is trapped in the attic, Kenny tells Christa about Lilly. If Lilly was left behind in "Long Road Ahead", the Stranger will criticize Lee because he abandoned a "defenseless, grieving woman" clearly referring to Lilly.
Clementine has the option of telling Alvin how Lilly's father, Larry, died and "she shot another woman" (referring to Carley), or "another guy" (referring to Doug). Depending on choices in Season 1 she can mention how Lee either forgave her or left her behind.