- "Let's get crazy!"
- —Kirsten, excited about her birthday party
Kirsten was born on 10th June, 1987, from a Unnamed Man and a Unnamed Woman, she is the daughter of one of Jodie's female colleagues, she is a rebellious, rude, sadistic and selfish girl. She invited many of her friends to her birthday. They seem to be (except with Matt) childhood friends and classmates.
Kirsten throws a party for her 17th birthday, and, at the behest of her mother, invites Jodie. Kirsten wants nothing to do with the girl, she subtly mocks Jodie when she drinks beer and smokes marijuana for the first time. She is seen at the party mostly with her female friends Jen and Emma.
Upon opening Jodie's present, a poetry book penned by Edgar Allen Poe, she becomes furious. She insults Jodie, saying she shouldn't have made the trip if she was going to give her such 'crap'. She then, with her friends falling into line, singles Jodie out and tyrannizes her.
If Jodie decides to take revenge using Aiden, she will call her a "devil" and accuse Jodie of trying to kill her when her mother comes home.
- Her father was never seen or mentioned throughout the game, suggesting that Kirsten's parents are divorced or that the man died.