Re: Is my BP underweight?
It's really impossible to say without pictures or even numbers to guess by. Even chunky snakes can look a little triangular sometimes (have their spine ridge prominent), when they get themselves in certain positions.
If she's eating regularly and not gaining any weight, you might want to have a vet check her out for worms...which isn't a bad idea to do regardless, if you don't know her background history. (Pet store ball pythons are almost always imported from Africa and may host any number of parasites)
Re: Is my BP underweight?
It's a great idea like Judy said to get a test for internal parasites just to be on the safe side. A lot of imports do come with little hitch hikers.
If you go buy a kitchen scale that measures in grams, you can actually see their progress from month to month. I have often thought my young ones were looking thin, when actually they were putting on a lot of weight and growing longer before they 'filled out'. They were growing really fast, and I chalk it up to rapid growth spurts when young.
It doesnt hurt to buy a scale regardless, it's nice knowing how much your animals weigh. :gj: