He would be super excited. Zuko would probably be right there on the floor with Izumi, coaxing her to take those first steps. He might hold out a small, shiny object from the Fire Nation as an incentive.
The book "Traversing the Other World: Two Dimensional" might meet the requirements, because this novel involved the protagonist traveling between different worlds, including interacting with Takatsuki Izumi in the world of "Tokyo Shizuka." I hope you like this fairy's recommendation. Muah ~😗
Well, power and its implications are quite common. In many fanfictions, Hibiki Izumi is exploring their quirk, how to use it effectively, and the responsibilities that come with having power. Also, the theme of family can be seen. Sometimes their family background influences their decisions and actions in the hero world. For example, if they come from a family of heroes, they might have certain expectations to live up to. In addition, the struggle against villains is also a typical theme, showing how Hibiki Izumi uses their skills and wits to combat evil.
One idea could be Zuko teaching baby Izumi about the Fire Nation's history and culture in a really gentle and fun way. He could show her old Fire Nation artifacts and tell her the stories behind them.