User blog comment:Samuelshadow16/Are Ruby and Yang Blood Related/@comment-98.127.74.142-20140724142015

They are blood-related, but they're half-sisters. According to Monty, Yang is not Summer Rose's (Ruby's mother) daughter, showing that Yang and Ruby don't share the same mother. So now, we know that Yang and Ruby share the same father, but have different mothers (though we don't know their father's name or who Yang's mother is yet). However, I'm still confused to how Yang and Ruby have different last names, but it's probably because to not draw attention to themselves. Well, we'll have to wait and see.