Well is she pulling fur on her tummy?? If she is, then she could be pregnant... but alot of female rabbits go through a phase called 'False Pregnancy' where they get all ready to have kits... and they aren't even pregnant. I would urge you to get the bunny spayed.

EDIT: Oh, just read your post, maybe she did have a little incident where she accidently ripped out her fur?

I suggest feeding Romaine Lettuce to your rabbit, iceburg lettuce isn't good for them, just makes them fat.

Good Luck with your new bunny!