No one here is in a position to say what you SHOULD do. We are not privy to the details or the parties involved. All anyone here can propose in this situation is what CAN be done, not what SHOULD be done.
You are right to be concerned, but until your husband is in a position to legally safeguard his child, she is free to do what her guardians allow her to do.
And, as a note, older kids - particularly teenagers - are almost always going to be mad at their parents or anyone trying to impose rules on them. So, yes, if your hubbie gets custody somehow and reins her in, she will almost certainly espouse anger towards him and towards you. It's the nature of things. I have three teenagers at home and a pre-teen, and if I wanted to be liked I'd let them all do whatever they wanted to do ... but it wouldn't be the right thing to do.