User blog comment:Samuelshadow16/Are Ruby and Yang Blood Related/@comment-24.158.202.97-20130929185825

Hmm.

1) Yang is two years older than Ruby

2) We've never heard either girl mention 'Mom' to this point.

3)What we've seen of their relationship so far covers the sister category pretty well; from the cat fights to the first to run to protect the other instinct.

Most likely scenarios are:

a) Adoption. Ruby as infant and Yang as toddler. They grew up sisters, and no one has said much about Ruby's true genesis.

b) Half sibs. Ruby was the result of a fling by Summer and Daddy Long. Or the Longs seperated -after- spawning Yang. Dad was with Summer long enough to spawn Ruby, then Summer bought it, and Dad showed up with daughter # 2 & Mama Long forgave and accepted him back. Or Yang was the fling results, and after Summer died, Papa-san turned to the mistress to forge a family for his daugthers.

c) The Big Secret. Summer gave the Longs Ruby to care for while she did something heroic, with a request that they raise her as their own if she doesn't come back. She doesn't, and neither girl knows.

Until the writers tell more, that'a as much as we can rationally conjecture....