How can I help if she won't let me

Hi there, now I'm at a total loss as to how I can help my partner, now she has had a really bad few years with people she loved turning on her and loosing her dad plus a few good friends of hers took there own lives, plus she has a 13year old narsasistic daughter who will do an say anything to hurt her mum, plus running away and staying out instead of being home like she should, anyway I came to stay with her 3months ago ,the daughter ran off to her 19year old boyfriends place and just lied and did everything she could to make people feel sorry for her. Not doing or listening to anything her mum asked.anyway she returned home 2weeks ago and was being really good until she wants to do what she wants then she just leaves. And end result was the father who has not looked after his daughter for one night since birth has rang child services on her, now they have to go through it all again and my partner has had enough of being run into ground and treated like crap by daughter and want as to give up on everything, I will do everything to help but she dose not want to here a word I say just keep saying she don't care and won't be here tomorrow .What do I do. Anyone got any ideas.