Board Thread:Episode Discussion/@comment-24666470-20151213083357/@comment-26397825-20151213085840

The leading theory is that the confrontation didn't actually happen; it was actually a dream made up by Yang's subconsious as an answer to who the lady (that she barely caught a glimpse of the back of as she was leaving, since Yang was unconscious just before then) that saved her life was, and why she saved her life. It was also enough of a glimpse for her to think, "Hang on, that woman is wearing clothing similar to my mum, and has hair similar. Could it be her?"

So later that night, since Yang says that her intention is to sleep after the events of Breach, Yang has a dream where she confronts the lady who saved her on the train, and overlays her features with the features of the photograph she has seen of her mum and what she saw of the lady on the train. Her subconscious then assigns a voice, and tells Yang they have a lot to talk about; referencing Yang's desire to know why she left just after Yang was born.

It was just a dream, thought up by a girl who is still looking for her mother after all this time.