I remember that being said too. Right now we have Hyur and Elezan children, the only distinguishing feature of the Elezan being the ears. If Ul'dah is your starting city, you see Lalafell children, but again, they apparently use the same models as adults.

In Heavensward, Roegadyn and Miqo'te children were mentioned specifically to be added, but probably Au Ra, too.

I personally wouldn't mind seeing a more obvious difference between Hyuran and Elezan children, becuase, if Alphinaud is any idication, Elezan must shoot up like weeds during their late teens, early 20s, otherwise that kid and his sister are TINY.