What should I do about my friend?

I've known my friend since I was born (I'm sixteen) and we've always been really close. In the last year or two she's been having loads of problems with her family (her dad, in particular) and I've always tried to be supportive. It seemed that her family had just got past what had happened (I'm not going to go into detail, but her Dad kept leaving then coming back, being horrible getting drunk etc.) when he left again, this time for like three months. Well, he's just come back and she's really upset, because he really is a massive idiot. She's already gone through it and doesn't need help forgiving him or anything like that, but now when I try and offer support, she clams up and won't talk to me. Would it show thoughtfulness if I keep trying to help, or should I giver a bit of space? I don't want to make her uncomfortable, but I don't want her to feel like she's alone. Can someone try and help?