Mine is 24" at the moment as well, and I switched her from small mice (5.0 grams) to medium mice (7.5 grams) when she was 22" as well, last month. From what I've seen on here and other supplemental reading, it's best to feed a ball one sufficient meal than multiple small ones. I'd try getting her something that's the same fatness as her thickest section. If those hoppers are a certain "brand" of frozen mouse, try getting some slightly larger mouse of the same brand. I say this because mine was used to Arctic Mice and wouldn't eat any other fuzzies when I tried to feed her a different brand I found at a cheaper price. But, your experience may differ. Still, one meal is better than many is the common consensus