I had the exact same problem, and mine is about the same size. I tried a mouse pinkie, nothing. Waited a week and tried a rat pinkie, nothing. Waited another week, and tried a fuzzy mouse, BINGO!! Now she's eating two fuzzies a week, and growing fast. If you just bought her, she could be still getting used to the enclosure. They are really picky eaters. Some even prefer a male/female mouse. Keep trying. You'll find out what she likes. And just when you do, she grows and you'll have to upgrade. lol.