Get her on frozen thawed rat pups ASAP, and feed every four days to get some weight going....then every 5-7 days. You do NOT want a mouser Burm and they can be pretty difficult to switch to rats once on mice. Albinism can alsio add feeding problems in Burms as well sometimes. If all she'll take hs mice, then use them to pack on weight but then keep trying to make the switch.
A majority of hydration is provided via prey items by the way.
I disagree about 10 days and very much disagree about going slow to start, the snake is underweight and in the hatchling stage, breeders feed every 5-7 days on a normal schedule. Also recomended by world of Burns, which is a group of about 20 Burm breeders. I respectfully wish people who have never owned one would research before giving advice in scenarios like this. These are not BP's and Colubrids, they have extremely fast digestive systems in this stage.