I... don't really know what to say.... I feel so sorry for you and your family
I think it's good that you didn't hit her, violence isn't always the right way...
I don't know what you could do with her... except for trying to talk to her, maybe as a whole family and make sure that she really knows the consequences of what she is doing. Maybe she'll stop being the way she is?
I'm so sorry, i have no real idea how i could help, i feel so bad know