I actually would recommend a heating pad instead of a lamp. It's really difficult to maintain humidity in an aquarium to begin with--having a lamp is going to make things even worse. You could use one to supplement your heating pad if your house gets cold but I wouldn't leave one on all the time. If you want to have a light (to view her), use a flouresent bulb
I know you don't know her age but how long is she (I'm assuming she's quite small if she's eating fuzzies)? That will help us determine what she should be eating
. By the way, I would try to get her switched to frozen (or at least pre-killed) if she's eating live. It might not be a problem now but it could get very dangerous for her to eat live once she's eating adult mice and rats.
Oh, and from the sound of it you only have one hiding place? Get another one for the other side of the tank. That way she doesn't have to choose between the proper temperature and security.
My other advice would be to make sure you have a thermometer on each side of the tank and a humidity guage (low humidity is a major cause of problems in ball pythons). Also, any heating devices should be connected to a thermostat to prevent over-heating.