Don't worry about it, its normal, you must have scared her. Just like slyther said, let her know your there. They can be in really deep sleep some times.
You stated that you hold her often, never during shed and a day before and after feeding... You should really wait 2 days after feeding to handle her. Handling them with a hardly digested mouse in her belly can cause a regurgitation, which is really hard on a snakes health. Just a heads up.
~ DZ