How are you sure that she is gravid? Just because she is big? If she ate she may not be gravid, although that is not a definitive indicator.

If you are really worried I would take her in to your vet and have an ultrasound or x-ray done just to make sure she really is gravid.

One x-ray on her if she has eggs (if the vet dosen't have an ultrasound) should not hurt the babies.