Oh Lord, then you are now officially on pregnancy watch. If she was in with a noncastrated male, there is every chance that she is pregnant, poor little thing.
Make sure you have a baby safe cage, just in case, and if she lets you handle her without too much stress you can start taking her weight every couple days. A steady weight gain, slow and easy, might just be from good food and good care, but if she continues to gain, look rounder, have a big jump of weight, then a levelling off and a little dropping, burrowing at the bottom of the cage, laying on her side (more than usual), change in personality - these could all be indications of pregnancy.
I will keep my fingers crossed that your girlie is not pregnant. With the head tilt already going on, that could be hard on her. I would definitely get her checked out by a vet soon.