Supernatural predator

17 year old Caroline has always been different from everyone else. She gets abused at home by her parents and it isn't any difference at school, beaten, pushed around, getting verbally abused too.
But 3 months before her 18th birthday she gets into a deviating car accident, the injuries being so terrible that the doctors say she will probably never wake up. Meanwhile when Caroline slips into this coma she is told that she is the one who will change what has been done, because she is the chosen one. In her time she is there training to be the perfect leader, a top fighter and a killer too all in three months, she also learns to unlock her abilities and master them. In the real world it has only been 3 months since the crash, and on the eve of her 18th birthday she awakes,even though it was said she never would. She now know exactly what to do.