Did she go through therapy too? Maybe she is resenting you becasue you are there and not her mom. This would be a difficult thing to deal with. Maybe she thinks she needs her dad all to her self.

I would try asking the husband to try one on one talking to her to see if he can find out what the real problems are.

Also you and him need to be on the same page when it comes to discplining the children and NEVER disagree with each other in front of them . They learn fast how to manpuliate that concept and play you against each other.

Maybe you and the kids could go to therapy together. I know therapy isn't always what will work but sometimes it will help.
Also maybe you could buy her a journal so she could write her feelings down, this is a age where a girl really needs their mom the most. she is also starting to go through puberty and they get sassy at that age .
Good luck and the best of luck