Go back to school and start over. Fuck him who cares about it. She obviously saw red flags if he called her names and hit her and she chose to ignore them. The best revenge is to forget. Tell her to move to a new town, start a new life. If she was capable of taking care of a grown child and his abuse she is strong enough to start over. Key thing I would do is hit the gym. Make it my new religion. It will relieve stress, give her more energy and make her feel better. Then go back to school and work hard. If she enjoys school and finds a job she likes then she will enjoy school and work and have fun while doing both. The gym is a big thing. It helps increase positive thoughts and will help her keep her energy level up.
Life is too short! She, from you said, has already given up part of her life to him, why give the rest to him by fighting and chasing. MOVE AWAY AND NEVER LOOK BACK. That means no calls no nothing. BYE BYE SAILOR!
