Andrea (portrayed by Laurie Holden) was traveling with her younger sister, Amy, when she encountered the walking dead.
Andrea was on a road trip heading for her younger sister’s college campus when they were stranded in Atlanta by zombies. It was there they met Dale and he helped them get to safety.
Using Dale’s RV camper as an anchor, Dale, Andrea and Amy set up a survivor’s camp outside of Atlanta. After the camp is attacked by zombies, Amy is bitten and killed, which forces Andrea to shoot her again after she turns into a zombie.
In the Season 1 finale, after the group finds out that the CDC is going to self-destruct, a depressed Andrea opts to stay with Dr. Jenner and die in the explosion. Dale, who seems to both want to be Andrea’s father and husband, sits next to her and tells her that if she was going to die, he was going to die too. That ploy gets Andrea to leave the CDC with the rest of the group, although now she resents Dale for putting her in that position and taking away her choice to die. When Andrea finds out that Shane wants to take off on his own, she asks to go with him.
As of right now Andrea has forgiven Dale, but still hangs around Shane, wanting him to teach her how to shoot. Feeling very gung-ho about shooting, Andrea almost kills Daryl with a rifle when he returns the farm limping and covered in mud, believing that he’s a zombie.
Still feeling a connection with Shane, Andrea and Shane have sex in a car after the two of them kill a bunch of zombies in a suburban community near the farm.