I usually weigh mine in grams. It sounds a little on the light side to me. My 2, going on 3 year old female weighs 11 oz. which is a little less than 3/4 of a pound or a little less than .75 pounds. In grams it's 318 grams. She's not real girthy in size either. Snakes tend to very greatly in size though, so it really means nothing. My 2 going on 3 amel male is 575 grams and over 4 ft. long. Far bigger than she is. I would just go by their health and general activity level. If they seem healthy, eat well, and active, I wouldn't worry about it. The weight is only important if you're planning on breeding.