there isnt really a strong correlation between age and weight in snakes. there weight will depend on the temps they are kept at (metabolic speed) and the amount they are fed. some people might be able to tell you how much theres weigh at simalar ages, but that is about it.
the only thing you can really go by, is the amount you feed them, and the weight to length ratio(how fat it is) to tell if it is healthy.
but they sound like ok weights in my opinion, but i havent reared a baby royal so wouldnt honestly know in depth.
Dan
