Board Thread:Speculation House/@comment-27151765-20151102160804/@comment-27397283-20160402194119

Often when a marriage bond does not exist between the parents of a child, the surname is chosen by the acting parent, which, in the case of Yang, was Taiyang, as Raven left not long after Yang was born. In Ruby's situation, as both Summer and Taiyang were active parents, the naming was defaulted to the mother. Now, it is possible that Ruby was the only child for the Rose family tree, so, Summer wanted to give Ruby the surname Rose to carry on the family, if for only one more generation.