So what you are asking is for example; if you had 2 clutch mates and the male pretty much reached his growth peak at say, 3 yrs , would the female still be growing for a certain period of time longer?

or -

Is it more like humans where males and females are similar in size until puberty and adolescence, and then, BOOM! Growth spurts occurs?

Not stupid at all, interesting question.

Maybe some breeders and experienced handlers will shed some light.