>>2 Agreed.
However, just telling another perspective isn't always going to change her point of view. If I were you, I'd talk to her about all the great things she has. All the work her parents do for her to live. The friends, and all the small little things that make her smile.
If she is serious on that note of leaving her house, I'd tell you to talk to your parents and ask her to talk to hers. That way if her parents act in a bad way, she could spend a couple weeks in your place, just until everything is ok.
I don't know how old are you, but if you are around 14-17 people are starting to date there, and it is very normal to feel alone at that age. Maybe she is looking for one of those movies relationships, and in that case, it is going to pass soon.
Best of luck~