|“||You totally hooked up with him, didn't you?||”|
— Kirsten to Spencer
In Wicked, it's revealed that Kirsten was born in Cape Town, South Africa. She was adopted, and her birth mom is also from South Africa.
In Ruthless, Kirsten and Aria are in the same Art History class which most of it's students find boring. Aria is happy that Kristen is the only other student that actually tried to do good in the class. Aria and Kristen what to work together before their teacher tells them she will pick the student's partners. Kristen gives Klaudia a glare when she smirked at Aria when Aria noticed Klaudia wearing Noel's grandfather's jacket.
In Burned, Kristen and Spencer share a room together on the cruise.