For one thing, you don't handle it. It isn't your responsibility. This is not a good situation. In spite of your feelings in the past about her family and her, you need to deal with things the way that they are in the present. It would be good if things could work out so that everyone is safe, happy, friends and free from the potential of harm. But, it doesn't look like that will be the case for awhile with this particular family. They need some help. You need to deal with the reality of the instability the way it is right now. Protect yourself and do what you can to try to help the entire family.
Absolutely don't speak to her by yourself! Please have a witness present if and when you do! Please don't touch her and avoid being alone with her. She could say anything about you, and that could lead to a real mess with the law and social service type people. Besides that, it isn't really your responsibility to be talking with her about this. It should be her parents.

Originally Posted by
Clough
Where is her mother in all of this, by-the-way?
I would really distance yourself from her if I were you and also any situation where she could try to do something to you. Sounds like both she and her family could really use some counseling!
It's okay to be concerned about her safety. Just watch your back as well.
I am sure that others will be along to offer their advice to you