My dads girlfriend is always starting shit

Jessica
Me and my man live  next door to my dad and his girlfriend she's always saying shit that isn't true like one thing she always says my man slams the door but he doesn't he comes in quitely but she still starts no matter what we do she starts I do not like her in my dads life and they have been together for 9 fucking years ever since they got together it's been nothing but trouble with her what do I do please help