Inquery asked: Little 9 year old Izumi develops a crush on Zuko, and by the time she's 13-15 she realizes that these feelings have only intensified and are here to STAY. What does Izumi do? Which parent finds out first? How does Azula find out and react? How does Zuko find out and react? What do they decide to do?
I think she'd keep it a secret and feel extremely guilty since she is likely to think of her feelings as a betrayal against her mother. Since she'd be really close to both her parents, they'd notice something is up, and it'd be only a matter of time before she caves and tells them what is going on. They'd be shocked, but they would obviously not think any less of her for it. While Azula would usually instantly see any woman who wants Zuko for herself as an enemy, she loves her daughter and would never want to punish her for something she cannot control.
Now, I'm biased as fuck, so I say that, while the situation is awkward, not much would change, and Zuko and Azula would just tone down their affection for each other in front of Izumi as to avoid hurting her, while Izumi herself is aware that nobody could ever separate her parents and she definitively doesn't want to do that, as they're quite clearly happy together and she likely thinks they're soulmates.
Though, of course, if you prefer it, Izumi can become his second wife eventually, and maybe even be involved with her mother as well.