Personally... I don't think I would run the risk of having my children around another child like that, especially when I was trying to keep the image that the parent of said child was my equal. My parents didn't spank me at 13, but you can damn well be sure that I'd get a good backhanding if I'd thrown something at them or berated them the way she does. Or even worse... my mom would have called one of her friends, who though she isn't a blood relative, I look at as my aunt... She'd have grabbed me by the ear and worn my ass out, or would have put me through some sort of manual labor... the dirtiest cleaning job she could come up with, most likely.
I've heard of people "working it out" in situations like these, but from what I've seen of human nature in general, its that people don't change. If he isn't enforcing the rules now, he's certainly not going to enforce them later.
Just wait until after you two end up married and she wrecks her brand new car that daddy bought her for her sweet 16 and he expects you to help pay to get her a new one. If it were me, I'd run as fast as I could.