Player character height isn't always reliably confirmed, but with enough digging (and using the size comparison feature in the pokedex in the games that it's available) you can make some educated guesses
> Ethan and Elio are confirmed 4'11" and at least one of them we know is because of the pokedex size comp page
> Lucas is confirmed 14
> It's insinuated that Calem is 16 and they reset the ages to 11 with gen7
