For female it is a combination of weight, age and body proportion, I will explain that by giving a few examples
I have bred 4 years old 1200 grams females. Obviously the maturity was there even though the weight was on the low end.
I have bred 18 months 1500 grams females.
I have pull out of breeding rotation 4 years old 2000 grams females. Those females checked all the boxes when it came to numbers but they look lean not plum (basically long slender females)
Ideally the bigger the better for me I don’t like to waste breeding on smaller females that will often give smaller clutches, but most importantly I am really in tune with my animals and observe them a lot, if a female will start showing be breeding behaviour I will take everything I just mentioned and decide whether or not I want to breed her knowing she is developing follicles.