offer her food every day before the water change (it has to be done every day and change 100% of the water). if she eats thats ok but because shes colder she wont want to eat as much. make sure you keep another container of dechlorinated water in the fridge also so you dont give her temp shock when you stick her into the new water
this is the way i do it (when i first put it in the fridge)-
*fill a container with tank water
*put the axie in
*get another container of equal size and fill it with fresh tap water and add dechlorinator
*put them both in the fridge
*when it comes to my water change the next day i offer food, if it takes it ok (leave five mins if it takes food), if not net it and pop it into the new container
*rinse and fill old container with fresh tap water, dechlorinate and repeat
hope that helps!