Re: Female shihan, or more accurately...lack thereof?
Our most senior student under Imaizumi Sensei is Donna Carlson. She holds classes as Shin Budo Kai Honbu on saturdays.
Recently I read "women in aikido" by seigel, and what struck me the most was the distance so many of the women being interviewed put between themselves and the aikido world. I sense many of them get what they want out of it, evolve, and leave.
With so few females in the art relative to males, it always makes me sad when I see a female aikidoist move on.