i have a 5 month old leopard gecko who is 7". i think its a female but not to sure. it never keeps still so ive only glanced underneath it to see if it has any bulges or femoral pores
Like mangocola said there is always differences in size and weight but usually just by looking at its size compared to other leos and its heathlyness its fine
we would need to see a picture, weight really means nothing without one. I only keep track of my geckos weight to see if they are gaining or loosing any. You could have a gecko who weighed 40g and one that weighed 80g, who are the same age and are both in good health, its just they are all very different.