I have mousers around that size and they get 3-4 medium adult mice per feeding. I make feeding rounds every 15-20 minutes until all the mice are gone. You can also try to skip a week with her, then the day before feeding day on the second week, bump the heat up to 94. She will likely be so eager for a meal that she will take a medium rat. Try offering it on tongs about a foot above her tub so she isn't intimidated, and I bet she'll grab it, no problem.