Diana Wynne Jones said this quote

“ Female Mercenary. This will be a companion on your Tour. She is usually tall, thin and wiry, silent, and neurotic. Sex scares her. This is because she either came from a nunnery or was raped as a child. Or both. Somehow this inspired her to become a mercenary and she is very good at her job. You can rely on her absolutely in a fight. She can usually kill two people at once while guarding your back in between. The rest of the time, she will irritate you with lots of punctilious weapons cleaning and a perpetual insistence that a proper watch be kept. Mostly, she will have no magic talents, but sometimes, in an emergency, she will come up with a gift or vision. You will end up grudgingly admiring her. ”