D: Uhhh... For the fight part, I'm actually not sure if it's okay. XD; Only because we're trying to finish the RP and that sounds like a roadblock sort of thing. If it makes things more interesting, then it's absolutely fine, but if it doesn't, then maybe we shouldn't do that? :<
As for the sibling thing... BLARGH. D8 When that's paired with what I have in mind for Rena, that makes absolutely no sense. .-. I won't explain it on here (I'll explain it in the RP, though), but she couldn't really have siblings.
Sorry if it seems like I'm just ignoring or shooting down your ideas. I'm not trying to! D: I'm trying to keep the RP moving, though, and I don't want too much focus on Rena in the RP... ^^;