Please someone give some advise. This story starts way back to when my daughter was 13 (now 17). She started out being the life of the party loved by everyone friends, family, first born on both sides of the family. Admittedly she is/was spoiled. However, at 13 she had a boyfriend of 16 we did not approve of. At the same time went out with an older group of kids (without our knowledge was spending the night with a girl friend spoke w/ parents did it all as parents do) was "raped" by an 18 year old at a party. The prossecutor said she was a willing participant. We were unable to prossicute the 18 year old because she had sexual intercourse with her 16 year old boyfriend willingly also. If we go after the 18 year old we must go after the 16 year old in addition. Knowing her boyfriend, even though we did not approve of there relationship we couldn't go after this kid. He is a very nice young man and couldnt justify destroying his future for her/their puppy love mistake. So we let this go. Went into family counseling, personal counseling for my daughter and moved on so we thought. The acting out continued....Sneaking out at night, very permiscuous with many other boys, very proud of her behavior like notches on her bed post. Boasting a school not caring about her reputation. I also at the time was working at the school. Very painful to us as parents, we continued with counseling, doctors of verious types to determine her behavior. No drugs, (has been tested), drinking, can be very sweet but has a real wild side. Nothing has come up. She has had migranes and was tested and has a small growth near her petuitary gland (center of her brain) which may or may not be causing the migranes. We made a decision to pull her from Public School to private Christian School hoping this may have some influence on her she just continued her behavior taking others down with her. Stealing petty items from stores, not caught technically her friend was caught red handed we thought this might scare her into some type of reality but she moved onto stealing from family specifilly her grandparents which was an enormous amount of money before she was found out. (Their nest egg of sorts) Yes of course we grounded her from all activities, phone, friends, tv all the things we thought needed to be done. We also have held her accountable to pay them back, we made her get a job, paying them what she could when she could, (this job also had random drug testing). Even had her sign a document written up by a family friend lawyer stating what she had done and her intentions to pay back her debt. Then again stuff started happening again, little things like small amounts of money missing, not really sure if its missing or we just used more than we thought. We started to keep better track of things again, and yes things were not adding up. She also stealing from her sister, money, phone card, gift card, makeup etc. She is now 17 in high school failing classes skipping school, she also is making up credits with night school which she is not attending or taking very seriously. The school has informed us she must pass all classes including night school or she will not graduate this year. She just doesnt care! We had to leave out of town for a week a couple of weeks ago and had my brother her uncle stay with her at our house with her to "baby sit" our 17 year old to make sure she stays on track. Just a few days ago I got a call from the school concerned about her missing a week of school. I was floored! She was left behind so she can attend school and she didnt even bother to go. My brother had no idea she wasn't going. She had forged his name on a note excusing her from school that week. The school knowing me found this suspisous and phoned me and questioned this note. When she got home I questioned her about her absense and note she lied and would not admit guilt. So in my fustration I informed her if she cant follow family rules and she thinks she can find someone else to live with that have no rules then get out and she did. She left the house and she hasn't been back in 3 days. I do know where she is. She is safe at a girlfriends house. I am rather upset with that family making it easy for her to run away from her responsibilities. I dont know I just need to know what to do at this point. Should I fight this or just let her go and hope for the best? 
Thank you! 
Worried and Concerned