Board Thread:Speculation House/@comment-9058532-20130807182204/@comment-3107614-20140808004317

Summer Rose is Ruby's mom, yes, but her father is most likely different from  Yang's dad but she most likely doesn't know it. They are most likely stepsisters but Ruby and Summer joined the family while Yang was very very yung, which explains why Ruby and Yang get along so well. Her father may be Ozpin, I hope it isn't Port, but it could also be OObleck, which would explain Ruby's semblance.