Not much is known about Gabi's life prior to or as the outbreak began, except that she had a sister.
After seeing someone wearing the hazmat suit wander away, Gabi continues to follow. Assuming that it is Sierra, Gabi is surprised by Sierra as she jumps out of hiding and puts a knife to her throat. Gabi explains that she was following her because she can kill walkers and she cannot, having twisted her ankle earlier. She pleads with Sierra not to leave her.
Sierra climbs into a guard tower with Gabi behind her and wipes her bloody knife on her suit pants. Gabi suggests they head south across the border into Mexico, claiming that it should have been overwhelmed with sick people trying to cross the border, allowing them to slip past it. Gabi also mentions that her boyfriend was with the Border Patrol and knows of a tunnel, but Sierra interrupts and suggests that her boyfriend is probably dead because he hasn't come back yet. While Gabi offers to take Sierra because she needs a place to go, Sierra reaffirms that she doesn't need Gabi to survive.
Gabi follows Sierra through the desert after they leave the military camp. As they approach the Mexico-United States border, she asks Sierra where she is from and apologizes when Sierra informs her that she was from Los Angeles and escaped the bombs. After being told to pick up the pace, Gabi shares with Sierra that she lost her sister to the zombies and then receives a lesson from Sierra on how to kill the zombies, that she should aim for the eye socket and not just the skull as the blade may bounce off of it.
Gabi and Sierra enter a fenced-in construction site when suddenly Gabi is attacked by a zombified construction worker on a chain. Sierra yanks the zombie away and gives Gabi her knife so she may practice defending herself. Before she can put the zombie down, a gunman shoots the zombie, splattering blood on Gabi's face.
Gabi is overjoyed to find out that the person who shot the chained infected is her boyfriend Colton, as she thought he was dead. She rushes to embrace him. Gabi admits to Colton that she and her sister waited at their former location for too long and that is why her sister is dead while Colton thought Gabi had died when "the bombs fell". She tells Colton that Sierra is the reason she reached the construction site alive, and that Sierra is the only person she told about the tunnel. She hugs Colton again, admitting that she thought Colton was coming for her.
After Gabi and Colton share an embrace, he instructs her to enter the tunnel. She pleads for Sierra to come with them and Colton complies and responds that he will be right behind her to close up the tunnel entrance. As Gabi waits in the tunnel, Sierra and Colton engage in a scuffle before Sierra joins her in the tunnel.
Gabi confronts Sierra about what happened with Colton. She seems shocked that Colton tried to kill Serra, and confused when Sierra tells her that Colton was left her behind and had never intended to bring her to the tunnel. She stands staring at the tunnel opening as Sierra runs on ahead, and turns just in time to see Sierra trigger a trip wire.
Gabi wakes up after the explosion that was triggered by the tripwire with ringing ears and covered in dirt. While Gabi is trying to get her bearings Sierra calls her a couple of times. Just as Gabi is about to get up and start looking for Sierra, a light shines behind her. She is then suddenly grabbed by someone who is revealed to be Colton holding a flashlight.
Colton grabs Gabi and tells her that she should have waited for him. Colton wants to go after Sierra and find her before "they" do. Gabi tries to protect Sierra and tells Colton to let her go. He doesn't listen, and tells Gabi to follow her. She does.
Gabi is walking with Colton, searching for Sierra. She tells Colton that Sierra is the reason she survived this long. Colton assures her that he is there to do that now.
Gabi is being led down the tunnel by Colton when they hear a voice. Colton hides Gabi and then goes to meet with a Boarder Patrol Guard. Gabi listens as they talk. Noting Colton's dishonestly, Gabi grabs a knife off a nearby supply shelf. When Colton comes back, Gabi asks him why he lied about the cause of the explosion. When Colton admits that the tunnel is also a bunker, Gabi comes to a realization and states that he was never coming back for her. As Colton tries to calm her, she draws her knife on him.
Gabi is not convinced by Colton when he tells her he wont hurt her. When Colton states that Gabi needs him to survive, she asserts that she can look after herself and turns her back to him and attempts to leave. Instead, she is dragged to the ground by Colton. They struggle briefly, before Gabi starts swinging her knife at him. Colton backs away, drawing his gun, leaving them both surprised at one another.
Just as Sierra is about to flee, Gabi gravely shouts her name for help.
Sierra comes in from behind Colton and tries to strangle him with some fabric. Gabi watches shock as Colton struggles to fight off Sierra but, eventually reaches for his gun. To avoid innocent bloodshed, Gabi picks up her knife and stabs Colton in the stomach. Stunned, Gabi is brought back to her senses by Sierra and is lifted to her feet. After realizing she had no other choice, Gabi runs away with Sierra despite Colton's pleads to not leave him for dead.
Gabi follows Sierra to a ladder that leads back above ground, however, they must sneak past a zombie eating one of the dead guards. Meanwhile Sierra slides past, Gabi is nearly grabbed but missed. Quickly, she successfully makes it up the ladder and gazes out to the city before them. Sierra offers her hand, to which Gabi grabs and shakes.
It is unknown what happened to her and Sierra, afterwards.
- "We waited as long as we could. You said you'd be back."
- —Gabi tells Colton about her sister.[src]
There's a possibility that Colton and Gabi knew each other before the outbreak. Being her boyfriend, Gabi seems to trust Colton with her life despite him disappearing for so long. After being separated, she ventured out to search for him and eventually found him. Considering all she experienced prior, Gabi proceeded to drop her knife at the sight of Colton and flee to him for protection, implying that she feels safe around him.
However, Gabi began to recognize her boyfriend's true ways overtime. When Sierra first told Gabi that Colton tried to kill her, she had a hard time believing it. Eventually, she learned that Colton was a man who cared about his own survival and that he didn't plan on returning for her or her sister. While he was in a scuffle with Sierra, Gabi stabbed Colton in the stomach before he could get the opportunity to shoot Sierra.
Gabi looked to Sierra for protection when she was at a disadvantage with her injuries. When Gabi first found Sierra, she noticed Sierra for her skill in defending herself. Although Sierra was hostile and threatened her, Gabi begged to travel with her because she figured she would not survive alone. After Sierra agreed to help find Colton and an underground tunnel, the pair traveled together and very briefly got the chance to know one another. Gabi then confided in Sierra and told her about her sister's turning and inability to kill.
Once Colton was found, Gabi was thankful for Sierra's company that she suggested Sierra come along to reassure her safety.