Hello libear2 and welcome to the forums! I hope you find the help you need here, and feel welcomed in the process!



You say you're using a heater under the tank that you got from a pet store? Are you using anything to control the amount of heat it puts out, such as a thermostat or a rheostst (light dimmer switch)? Those heating pads WILL get far too hot if left plugged directly into the wall without some kind of control.



What are the current temperatures inside your tank? What are you using to measure them? If you are using the little stick-on analogs from the petstore (either the round ones or the strips) you are very likely not getting anywhere close to a true reading. Besides being highly inaccurate to begin with, they are also almost always placed in the wrong spot to measure the temps you need to know.



It is possible that your snake has suffered some burns to her belly. A trip to the vet (one with experience in herps and snakes is best) would be a very good idea for you. In the meantime, if you'd like to describe your setup for us, we can help you get her environment turned around into something she will be healthy and thriving in.



How big is it? What substrate are you using? What heat sources and thermometers are you using? Are you measuring and maintaining a certain level of humidity? How long have you had your snake?



I know it's a lot to type out, but the more details we have, the more helpful we can be.

PS -- I moved your thread into the ball python husbandry forum for you.