You sound like you got it down but the heat is a little excessive. I have found that with high heat or low heat there is an impact on feeding. Ball pythons can be picky about feeding but should do well when their needs are met. I try keeping it below 90 at the most. As far as humidity goes that's always going to be an issue unless you get a rack setup properly with the right amount of ventilation. I can't see your pictures but in case you have your setup in a screen top tank try covering some of the screen to reduce the amount of ventilation. This should help you keep your humidity up. Prey size really depends on the size of your snake. After you let her get acclimated to her new home for a week or more try offering her a weaned rat and see if she takes. Again depending on her size you might want to offer something a little bigger. If she doesn't take to rats try an adult mouse. Even with my setup being in a controlled environment I have found that a number of my snakes still know when it's winter and will fast or hibernate. It's really hit or miss but there should be no cause for alarm unles she starts loosing a substantial amount of weight.
Welcome to the forums and feel free to reach out with any questions you may have.