Boy, does my heart go out to you right now! (((HUGS))) and :kiss to you!
I went through a divorce from hubby number one in 1988, we had three daughters, two told the judge they wanted to stay with me, the middle child told the judge she wanted "daddy". He wanted her, and only her...so sad and sick, I know. Well, since the courts listen to the kids and not to the parents, my middle daughter got her wish. She was with her dad all of six weeks before running back to me. He tried to force her to return to him, but the judge said "It's the child's choice!"
To make a long story shorter, this same daughter had us back and forth in court for change of custody, due to her change of mind, at least three to four times. The stress was tremendous, to say the least. She was thirteen at the time of the divorce, and at that age kids are so impressionable. What they say they want, isn't always what they want, but try telling them that.
Looking back at what I went through with that one daughter, if I had it to do over again, I would've said to her "Daughter, this is the last time you get to change your mind and put me through this court system. The next time you decide you don't like Mom's rules, and you run home to Daddy, that is where you will stay until you are 18". I didn't have the heart to do that then. I loved my girls so much that I would have done anything to make them happy. I didn't mind her living with her father...if that's what made her happy, but it didn't make her happy. She played us both against the other, and didn't like either one of our rules.
Teenagers...especially from divorced homes...don't fare well emotionally when those hormones are raving throughout their bodies.
IMHO...state your heartfelt feelings to your daughter about you not wanting her to leave your home and your protection. After sharing your heart with her, allow her to speak and say what's on her mind. If she still wants to go live with daddy, and you don't think she will be in harms way by living with him, let her go. Sometimes our kids have to find out for themselves certain lessons, especially when they are pre-teen and teenagers.
I'll be praying for your situation, you, and your daughter!