Board Thread:Speculation House/@comment-33464215-20171121150619/@comment-4010415-20171202085507

I doubt it'll ever be more than mere headcanon, since Monty said Ruby and Yang are half-sisters, which means they biologically share a parent. Since they have different mothers, that means they share a father. If Ruby's father is Qrow, that means he's Yang's father as well, which would mean that Qrow had sex with his own sister, which is a big no-no.

I think it makes more sense that Ruby bonded so strongly with Qrow merely because of the circumstances of her childhood. Think about it: Ruby was a very young child when they lost Summer, and Yang said that Tai was shut down at that time. That would mean that the only somewhat functional adult in Ruby's life at the time was Qrow, and we've seen that he enjoys spending time with Ruby and Yang in a very cool and fun way - telling them about his missions, playing jokes (his short skirt innkeeper story), playing video games. With Summer gone and Tai shut down with depression, Qrow was the only adult around to make a positive impact on Ruby for quite a while in her early formative years. It's no wonder she bonded so strongly with him and began emulating him.

When it comes to family, Ruby and Qrow consider each other family despite not being blood-related because family is more than blood. Hell, growing up, I called some of my parents' closest friends my aunts and uncles despite there being no blood relation there because they're so close with us that they're practically family. And they still treat us like family, so I will happily still regard them as aunts and uncles.