Board Thread:General Discussion/@comment-14640999-20141031215933/@comment-68.49.230.229-20141102023930

I thought it was understood that Yang and Ruby are half sisters, same dad, different moms. Both Yang's and Ruby's moms went on different missions and disappeared (presumedly Summer Rose is dead but no body to retreive) and Ruby was given Summer's last name as a form of identity to being hers than Yang's mom.