Other people are abused and some suffer mental illness while some who are abused do not. Some people suffer mental illness because someone owes them $5, and that is enough of a stressor to push the mental illness to the surface. My point is that the girl has a mental illness, and the abuse just brought it out in the open (something would have eventually), but she will never "recover completely" unless she has a brain transplant. Her "recovery" will be a lifelong parade of psychiatrists, mood swings, and a generalized sense of anxiety. Unless you have the patience of a saint, you should probably bail now before it wears you out.