Board Thread:General Discussion/@comment-26099499-20150226151824/@comment-25801533-20150318034726

Spiegelmeister wrote: I just won't buy the sister route. Yang didn't even know she had a different mother from Summer until she died, and even then it was a while later before Taiyang revealed it to her. In the 'dream sequence' she visibly reacts to Raven's face immediately, and then turns to anger with her red eyes before any line about "we have a lot to talk about".

Clearly, she knows the person by their face, and is angered by who they are. If it was a sister she didn't know about, the reaction wouldn't make sense. Even for it to be her mother who she's supposedly never physically seen before it seems a little bit of a stretch unless Taiyang gave her a picture, or she found one on her own in her search. I would gather from the flashback that she had a picture of her mother and thats how she is able to recognize Raven (if she's her mom).

On the note about her eyes turning red, I'm not sure it's strictly an anger thing. When she was talking with Blake she wasn't exactly mad or angry, but moreso frustrated or emotional. We see that she is a very compasionate person and cares about Blake and thus would more likely be frustrated or worked up emotionally than in a rage.