Just curious, but at 3-4 feet do you normally feed her 1 mouse or several? Or was this just a re-introductory meal?

If your sitter was just feeding 1 mouse every week, that may be a cause for some of her foul temper as that is a small meal for a 3-4 foot snake, and also explain her skinniness. At her size I would imagine a medium rat would be a good meal, depending on her size.