User blog comment:Wingzard/Did U Guys Join the Q&A on Twitter?/@comment-98.228.78.40-20130620044818

Yang has a different name because her name (Yang Xiao Long) is really a Nom De Guerre. That means that her name is a sort of stage name for bounty hunters. Her name means little gold Dragon of the Sun which is far too accurate to be a given name. Also she tells junior that she has many names. So they might be blood related with the same last name but they might not ever be called by their real names.