Board Thread:News and Announcements/@comment-6493589-20151008152837/@comment-5414218-20151013135308

I mean that if they didn't care about making a dog fit in a tube of that size and being sent via mail(basically just for the laughs), they won't care about biology or genetics.

Yang's mother is pretty much confirmed to be Qrow's sister. If her surname is Branwen and Raven was her daughter, she would inherit her surname Branwen as well.

Again, I agree that Raven is Yang's mother, but the possibility of her being her sister is not too crazy. And honestly it would be a better twist to have a new character with clues about Yang's mother rather than just solving the mystery five minutes after it's presented.