User blog comment:Ajrep1994/Yang and Ruby are half sisters/@comment-3257939-20140723235141/@comment-11188061-20140724131443

We know that they at least follow some of our customs - Summer Rose, Ruby Rose, so surname passdown is still there - at least, so it's still possible.

Also, I literally can think up an entire backstory why Yang chose to be 'Yang' and not 'Xiao Long' instead. I'm still waiting to see if my theory on her background is correct, but Gold in my opinion already describes why she chose to be Yang, 'the Sun'; to be the caring sister and not the wild fighter (referring to the Dragon) she once was (we can see her going a little battle crazy at Yellow Trailer - how many people can smile like a child when they're fighting hordes of men?).

Don't you worry about the dark,

I will light up the night with the love in my heart.

I will burn like the sun,

I will keep you safe and warm.