I agree that for her to regurge a small mouse is very odd. They can start rat pups practically from hatchlings. I'd try those, they will help her put on weight faster, IMO fuzzies are way too small, which is probably why she's growing slowly, hence the shedding issue. They all grow at different rates. Mine generally shed every 1 1/2-3 months.
On and the shedding process can take weeks. Sometimes from the time I see a pink belly (if I catch it) to the time they go blue it's almost 2 weeks.