Feeding Ball Pythons

:Hello, I'm a first time snake owner I have a female Ball python, she was about 20 inches long when I bought her and was about 3 months old. I've had her for about 3 weeks now, The first week and a half home she refused to eat, I do live Rat pups, She has a 45 gallon tank with 4 different hides, We also have a heat source for her, we have a warm side and a cool side. I have temp gauges for both sides of her tank as well as humidity gauges. The warm side stays at about 82 to 85 degrees F. And the cooler side ranges 10 degrees cooler. Humidity through out the tank is about 55 to 65%. The first time I fed her was a 3 day old baby Rat pup. And she was very greedy. 4 days after eatting it I noticed she started "pacing" around her tank. She gets very anxious, So today I bought her a week and a half old Rat pup. bit bigger and more "meaty". She took it instantly and very greadily, She had the entire body down within 3 minutes of striking it and now she's pacing around her tank lifting her head towards the lid and flicking her tongue everywhere. Should I up her feeding? I don't want her to pop from over feeding her but I DO NOT feel she's ready for a small rat. She's mu h to small for one.