Re: Female Sensei
I don't directly, but I do visit one reasonably regularly. I travel fairly regularly down to Monterey with work and call into Aikido of Monterey. Danielle Smith is the dojo-cho there that I train with. Within my own center, which offers multiple MA's, one of the two primary Hapkido teachers is a female, Susan Mix (5th Dan).
There's also a number of females high up in the California Aikido Association (Pat Hendricks, Cyndy Hyashi). At least in my experience, female martial arts instructors are reasonably common.