15 year old hates my partner

Help with 14 year old and partner.

Hello, my 15 year old hates my partner of over 4 years. She’s never really had relationship with her real Dad.
We’ve recently moved into our own home and she can be so hard work. She’s got attitude and doesn’t like rules we want in place. When either of us says anything she’s gets in a mood and it causes arguments, she starts swearing at me and him and he gets angry and they argue. I’ll always have my daughters back but she’s got to stop causing issues over nothing.
Me and my partner had an argument and we’ve temporarily gone back to my parents, now I’m wanting to go back she will not because she says she hates him and she’s making me feel so bad if I go back, making out I’m choosing him. I’ve tried talking, explaining to her etc but she’s just closes up and gets snappy.
Please help!!!