Choban Choban:
Sadly there will be no satifactory end result, the bully will not face any real punnishment and will return to school to bully again. I don't think criminal charges are the answer to things like this, I don't know what the answer is but minor charges in the youth justice system won't deter anyone.
The criminal charges aren't the answer because if she if locked up, she'll just be bullied by the other inmates, learn how to bully even better, or become the top bully herself. That's what's wrong with sending kids to jail, they just become toughened up by the system and learn how to be better criminals.
Better to have the school get involved. Do group stuff with the kids to make them better connected with each other.