I was fortunate to get my kids through puberty with a partner.
From the outside this looks like a fairly typical pushing on boundaries and weaponizing the fact that her parents aren't a united front.
I have no fabulous advice other than to be the sane parent and ride it out.
On BD H52, W50 T27, M26 S21, D23 BD-9-Mar-16 D-15-Jan-18 Final-19-Apr-18 I am a storyteller. The story may do you no good. But a story is never for the listener. It is always for the one who tells