So you know how Su was talking about wanting to turn over a new leaf and what not? I think that she and Aiwei used to be affiliated with Zaheer in the past but, not agreeing with his ideologies or thinking that his visions were too extreme, they decided to branch off from him and from the Red Lotus (if it was formed back then). I think they tried to move on but Aiwei didn’t completely lose faith in Zaheer’s ideals, unbenounced to Su. And then he betrayed her and she was forced to come to that reality and that’s why she was so shocked and devastated and shifty acting because she didn’t want to give away that they had known Zaheer once upon a time.
That would make sense….