I think FFXIV did a great job of representing young characters. Think of the Conjurer story quest for example: they look like real kids, no adult features that are common in anime kids.
That being said, I'd love to be able to play a scholar or a conjurer kid avatar. I understand playing a kid gladiator would be a bit ridicolous, but for mage roles it looks good.
Think Kid Rydia or Polom and Parom.