She is the former best friend of Ever, who turns on her and basically becomes evil. (Granted she isn't evil until later in the series).
Anyway I would cast Taylor Cole who plays Vicky Roberts on "The Event." She is a little old to play a teenager, but that isn't unusual. Anyway, she was on an episode of "Supernatural" and she was a really nice girl and I could see her being a best friend. I also know she was on "Heroes," but I don't remember her character at the moment. On "The Event" she is really tough, has little remorse for what she does, she is very determined and can be a bit of a biotch. She would be perfect to play Haven, not to mention she has the dark hair and she is pretty.
Anyway, in my head I think she is a perfect pick. She looks innocent, but can be really evil.
