My teenage daughter falsely accused me of assault, what do I do?

Last Friday my 15 year old daughter with bipolar disorder went to school and accused me of assaulting her the night before. There was an argument on Thursday evening at our home and she attacked me in front of my mom, my son, and my 2 younger daughters. No injuries were inflicted on either party and no police report was made. According to the ACS, she arrived a the school with scratches and bruises and was transported to a hospital (she left for school without any injury). I was arrested and now out on bail for a crime I didn't commit and am scheduled to return to court tomorrow. My daughter has a history of violence against her younger sister and a history of mental illness. A PIN was placed and she was placed in a mental treatment center by the court earlier this year and ran away from there. I brought her home recently because I feel that the treatment center was not a safe place for her. I was asked to sign a voluntary agreement with ACS and she is now in their foster care. Please help. I don't know what to do.