How much does she weigh, and how much do her feeders weigh? A bite/wrap is a food response rather than a defensive response.

If she's a big girl and you're feeding her a small rat, she may need a medium. Also there's a ton of variation among feeder vendors, I recently picked up a bag of 10 "small rats" from a local source that all weighed between 95 and 110 grams, while the "Arctic Mice" brand small rat is 50 grams. So, make sure you know how much food she's gettting, right now she's telling you she's underfed.

Two tricks I've used so that my snakes don't mistake my hand for food:
- Wash them well in cold water, snakes like warm food.
- Lemon-scented hand sanitizer, snakes don't like the smell. Alternatively you can rub a few drops of white vinegar over your hands.