Ideal weight and the weight one starts them at are probably way different.
Ideally I like my snakes to be well over 1500 grams before breeding, but I have bred 1200 gram females that made it to 1500 grams before developing follicles.
Most females will eat like pigs after being introduced to a male, but there's always some that don't eat well and are destined to throw slugs if they drop anything at all.

We have a clutch that just pipped from a 7 month old 440 gram fire male, that's as small as I have bred a male successfully.