Board Thread:Speculation House/@comment-25574297-20141024020130/@comment-165.234.190.64-20141102194752

We already know Yang and Ruby's dad's name is Taiyang Xiao Long. It was revealed back in episode 8.

We can assume Raven is Yang's mother due to the similar eye color (Monty specifically mentioned that eye color was the strongest connection between related characters)  and the name Branwen was added long ago by a monty account for the last name of Qrow, Ruby and Yang's uncle. So there's enough precedence to assume that Raven is related to Yang. Whether she's her mother can be argued, but Raven is definitely her relative.