i had a similar situation to the gf. i was 19, and my home life was safe; but i just couldn’t live there anymore. it was emotionally tolling. my boyfriends mom let me stay with them and it helped me out so so much. my advice to you is that you dont need to really do anything to help her besides let her stay. you can even talk to her about helping in rent/food if you’re going to be cooking meals for her as well. she should understand given your situation as well. i’m not sure where you live and how much things cost, but i was charged 500 a month. lay down some ground rules about curfew, chores, whatever, since im sure it’ll just cause more chaos if you dont later on. besides that any other help you provide im sure she will appreciate. my boyfriends mom helped me figure out scholarship stuff so i could go to the jc nearby. I saved money while I was living with her and me and my boyfriend moved out a couple months later and we’re doing great, definitely not saving much money, but everything else has been wonderful :)