Haha perfect. Glad she can hear now. But lol yeah, maybe a little early to start.

Honestly I wouldn't know really, I think it's all kind of subjective. My nephews started expressing interest anywhere from 4-12 years old. Exposure can/will help though usually. The nephews and nieces that saw and heard me or my BIL play more got interested earlier. A ukulele is kind of automatically in an open tuning so you can just strum or pick the strings without even doing anything with the fret hand and it sounding nice can encourage them to learn more - when you can just make something that sounds nice with minimal effort it will make it easier to apporach. I didn't even teach them any chords at first. Just kind of show like, how much you can do with just going up and down one string with even just one finger can make something that sounds nice. Kids are still developing the muscles their fingers and motor functions, just like adults who don't play or use their fingers in such a way, but I think it might be even harder for kids. I can remember a hundred times I almost gave up be cause it was just too hard physically to hold the chords, especially on an oversized classical guitar for tiny child hands.

Like you can even try for yourself. You don't even need to tune the uke differently, just strum the open strings and then go up and down a basic scale on the highest pitched (E) string (on the bottom of the neck): 0-2-3-5-7-8-10-12 frets, in different variations and find a melody. You don't need to do anything with any other string, just strum the open strings along with that one string. Just as an example. From there just expand the same mentality to other strings and start using more fingers. Too much theory can kill any interest very quickly and personally I think it's such an ass-backwards way to approach music. Like learning grammar and how to write before learning to speak.