In my opinion it sounds like she was just hungry, a year old ball python will need more than 2 large mice, my yearling old could eat 3 large mice and barely show a belly bump. She was still hungry probably and mistook the quick motion of your hand for prey. The smell of blood from your finger probably got her excited and that was why she was stiff when you handled her afterwards. Feed them a rodent that is as wide or maybe just slightly wider than the widest part of the snakes body, this is a good meal size, just feed the one. Mice are usually too small for ball pythons at that age, so rats would be a better choice, not only that, rats are supposed to have less body fat, and can be a leaner healthier meal for the snake than mice, atleast this is what I have been told on more than one occasion. At night I would also reccomend maybe keeping the ambient temp atleast 80 F, some people dont mind it getting cooler than that, but I dont like it to get that cool, and my pythons have seemed to do well at that night time temperature.