^ I ignore all the ages all the time

GRRM has even acknowledged that he done fucked them up. He was originally planning on a time hop aging everyone up, but then timeline shit happened, and he ended up having to cancel that, so everyone's younger than they're "supposed" to be. (Not that that changes early storyline for Dany...) Other than that, he doesn't have kids, so I think he's a little removed from how kids age.
Even if in a medieval type society kids had to grow up faster, some of the stuff is a stretch...

So I always imagine everyone like 3 years older than their book age, depending on who it is