Board Thread:General Discussion/@comment-26099499-20150226151824/@comment-226878-20150715025949

Typically, only theories that make sense within the context of current information in the show have been proven correct. Other information required outside confirmation (oft redacted) before it would be admitted here but the fact is that it is not RT's style to drop a chaos ball at the climax of a season/volume just to stir curiosity. If Raven were anything BUT Yang's mother, she would have been introduced mid-volume, not at the end. It wouldn't have to be a wholly obvious intro, just a silhouette on the wall (as an example) and they would have to be introduced in a context completely unrelated to Yang's mother. That means that the episode (and a few episodes before and after) cannot mention Yang's mother at all and preferrably would not share mother themes. If Raven were to be Yang's sister, then someone somewhere would have to speculate at least the possibility of Ruby and Yang having another sister even if only hypothetically (maybe Nora could wonder what Yang would have been like had she been raised by her mother).