Used to be an "angry teenager" until the bomb changed everything
Jane looked pretty normal until she dyed her hair black and red and started wearing black at the age of thirteen. She's sixteen now and hasn't changed much. She's not conventionally smart, but she has great intuition.
Before the bomb hit, Jane was extremely quiet and moody. She yelled at her parents, at teachers, at everybody. She didn't think anyone understood her. Now that she has quite a lot more on her mind, that might change...
A purse with various items inside (hairbrush, change purse, phone, ipod, etc. etc. etc.). Not much that's useful.
Jane came to the city on a school field trip when the bomb hit. After the confusion started, her inner genius told her to run away from her teachers and classmates. Brilliant move, Jane. Now she's all by herself and totally confused.