I couldn't find a good shot but it looks like in KH1, Sora reaches just above Leon's crotch. So it looks like Sora only got about six-ish inches taller in KH2. (Still going by Squall's official height) This puts Sora at somewhere around 3' 8" in the first game...
My braaaaaaaaaaain! That can't be right! They can't be that short! Whyyyyyyyyyyy!? *brain explodes*
Guh... I think I'll look through... the game more... I... Must... Know... Correct... Heights...
How about comparing KH2 Sora and Leon? That might give us a better perspective since it seems the proportions in that game are a bit more... refined, I guess. It's rather "amazing" to think that Sora is that short even as a 14-year-old...