Hello Bananabeep, welcome to Psych Central.

Let's hope that they break up again real soon! Yes you need to keep yourself safe during this, when they break up, make sure that you support her to keep away from him, she deserves much better. Often a female will choose an abusive partner when they feel badly about themselves and have very low self-esteem. Maybe you could give her some literature on that or direct her to this website. If you try to interfere to much it will have the opposite effect and she'll purposely try to prove you wrong so try not to get caught in the middle, again stay safe.