They prefer to eat live and sometimes will zero in on your body temperature. Power feeding is when you constantly feed every few days. Doing it once in a while shouldn't be a problem. She was probably fussy because she was in a new environment and many BP's won't be too interested in prekilled rodents because of the lack of body heat. Now that she is settle in the hunger is probably getting the best of her. I would recommend live, I feed 100's of BP's that way.