She looks a lot like a friend of mine who is rather nice but not exactly an easy person to be friends with..
This High Priestess looks calm and determined. Maybe she is feeding the mice to the cat? Somehow I feel that she could be connected to the Nature from the darker side, you know, from the not-much-talked-about side of things like decay, death, and all the raw edges of the meat-eating side of the natural world. Usually, when we talk about Mother Nature we want to just think of the pretty procreating bunny and Empressy side of it.
This High Priestess could be someone who breeds and tests mice in a laboratory for research purposes. Maybe for developing a vaccine against the swine flu? Something that may seem to be evil but in the end is not.