If her eyes look milky, you'll definitely want to keep the humidity on the higher side until she sheds... after that you can lower it down to around 60%. As Lily said, you'll also want to give her a hide on the warm side as well as one on the cool side -- she needs to be able to pick her ideal temp and not have to choose between feeling secure, and feeling warm enough...
Sometimes it will take snakes a little while to settle in and get eating again after being moved to a new home... give her a bit more time before you really start panicking
Also, just a note -- a mouse fuzzie is quite a small prey item for a 5 month old BP. If I'm not mistaken, even hatchling BPs can handle rat fuzzies -- so if your girl is 5 months old she should definitely be able to handle those if not small rat pups/adult mice...
Hope that helped a bit
Jen