J.L.
I recently went through this with my older kids (16 and 14). They actually came home and begged me not to "make" them go back. I won't go in to all of why, but they had many good, solid reasons not to want to go, and I had nothing to do with their decision.
To honor their wishes, and I thought to keep myself out of trouble, I said I wouldn't "make" them go (we had a central meeting spot), but if he came to get them I wouldn't be able to stop him from making them go (legally). He never came to get them. I tried to explain things to him (HA, ever talk to a wall..?)and got nowhere.
Long story short, we went to court and I was not allowed to explain anything...I was held in contempt of court for not forcing my teenaged kids to go where they truely didn't want to go and into nasty, dirty living conditions. The judge scolded me for "putting them up to" this and made untrue and unfair accusations about me instead...
So BE CAREFUL!!! Look out for your daughter, but use caution and follow the advice of an attorney, because if her father wants to make an issue out of it he CAN cost you a lot of money and tons of heartache.
Also, WRITE DOWN EVERYTHING...If your daughter doesn't want to go, document what she said, when she said it, date, time. circumstances...KEEP A JOURNAL of ALL things, good and bad. If she comes back with a story, a bruise, dirty, sick, whatever...WRITE IT DOWN. I didn't do this when it was suggested to me and it came back to bite me.
At her age, she may just want to be with Mommy and not have to hassle and have a messed up schedule. If there is something else going on there will be signs.
Good luck and hang in there.