L.B.
My husband went through the same thing when my daughter was 11. She felt like he was trying to take me away from her. I had to sit down with her and pull those feelings out of her. I told her that the proper order of a family is a mom & dad first, and the children 2nd. And just like any adult/child relationship, if I'm not present to give instruction on her behalf, she needs to obey the adult that I left in charge in my absence (as long as they are not instructing her to do something wrong). My husband was more of friend to her than a parent most times but the love was there & she eventually saw it and learned to love him back. It's not easy, hang in there & she'll eventually come around. She needs to see the love & respect first. And try to spend some one on one time with her if she'll allow it. But do not let her walk all over you either. Respect goes both ways.