Listen, if Toph had went off on her own for a while in Ba Sing Se there is no way she wouldn't vibe with Zuko.
"Welcome to Pao's Family tea shop, I'm Li, waddaya want?"
"Chaos."
"Understandable. Sadly, that's not on the menu. Would you settle for a cup of Jasmine tea?"
"Sure."
Jet, bursting into the tea shop: THOSE TWO ARE FIRE BENDERS! Toph, interrupting Zuko who is about go attack this mouth wheat boy: And where’s your proof? Jet, suspiciously: I saw the old man with a hot cup of tea right after he complained that it was cold? Toph, about to cause some chaos: Then clearly, you need your eyes checked. Toph, gesturing to Iroh: This man is a Water Bender.
THIS MAN IS A WATERBENDER