Are you a Brit?

If so, can you help me pick a first name for a female (late 30's or early 40's) character in a work of fiction I'm writing? The name needs to fit a rather spunky, intelligent, adventurous, somewhat fearless by nature type who will be one of the two main characters in my book. She will be, more or less, a co-hero with the other main character, a male American. All suggestions considered.