I'd have to agree with the excellent advice here. My first instinct would be to call 911 when she does get violent. But before she gets violent, make it clear to her that, while you will do everything you can to get her help, there are still consequences to her behavior. As a parent, the instinct is to protect our children from pain and getting hauled to juvie is painful (spent a few nights there myself in my younger days). But it's also important to help them learn to function in society by understanding consequences. I hope that helps...