I personally think it depends. Some females are naturally small and won't grow super huge. Doesn't mean she won't throw healthy clutches.
I have a pastel girl who is tiny compared to other females much younger than her. I got all my snakes as hatchlings and feed them w/ the same size food at the same rate. She's not skinny or anything, just now growing as much as the others.
I agree with the age thing. I'll wait till after the female's second winter before thinking about breeding. (even when the female is up to breeding weight....)