Actually, I picture Zuko as the more obvious problem. I think, skilled manipulator that Azula is, she would try to turn the situation to her advantage and comply with her uncle on the surface, while whispering in Zuko's ear how frightened she is of Uncle, and how much he needs to fight, and generally get Zuko to do her dirty work and try to sabotage Zuko and Iroh's relationship as much as possible. In short, she need a gag...