My dad hates my best friend?

Well, here's where we start off: my bestest friend in the whole world. My dad doesn't like her because she is agressive and she back talks and she "disrespects" him and his girlfriend. My best friend, let's call her, "rebecca" Well, Rebecca has gone through a lot of crap in her life, she has four other siblings, and her mom gets sick a lot, and her dad is a complete butthole. I don't think my dad understands how much Rebecca has been through. And my dad's girlfriend said that if Rebecca disrespects her next time she's over at my house, she's gonna take rebecca straight home. I'm really mad at my dad and his girlfriend. Oh, and I'm thirteen, so no, I can't run away or shizz like that. Help! :(