User blog comment:Ajrep1994/Yang and Ruby are half sisters/@comment-3146930-20140723223108

Kind of figured; it was the only theory that explained why they have last names different from each other, yet are still blood related and not cousins. As far as parents go, Summer Rose is Ruby's mom, but probably not Yang's considering they talk about their dad as if he is the same parent to both of them. Question is who is Yang's mother?