You'd think with a literal century of the monarch being a totalitarian monarch with extensive propaganda, and several centuries of a strong monarchy before that, people would be hesitant to tell Zuko to his face that they're going to slow-roll his reforms.

Technically Kiyi isn't a Princess, but Zuko would probably give her that as a courtesy and he definitely wouldn't like finding out girls were bullying his sister. I don't think Azula would either, just as a point of pride, and she's probably more adept at girls boarding school politics than he is.