There are many variables, hatch date (whether the snake hatch early in the year or later), weight out of the egg, how fast the animal got started, how big of a prey they are being offered and how often (some breeders offer food once a week some do once every 3 to 5 days)

I have a female that just weighs in at 120 grams (here is why http://www.ball-pythons.net/forums/s...ad.php?t=88610 ) while her clutch mate weighs 3 times as much.

And I also have a female over the 500 grams mark.