Where is the fury that the all men's classes threads endured?
What about a knife makes it a female weapon?
As I recall, Sokaku Takeda usually carried a knife hidden inside his kimono, and he never seemed very female to me. The naginata was traditionally taught to men (and still is in many koryu schools) - it didn't start being used by women until later on in the Tokugawa era and then caught on with women as "Atarashii Naginata" in modern times. I don't think it had much to do with body mechanics.
If women have such different body mechanics then it would only make it more imperative that they trained with men - since they would need to learn to deal with the different body mechanics employed by male attackers. Are there many self defense classes for women that have them focusing on female attackers?
I'm still waiting for the "short skinny guy's class" so that I can focus on my unique body mechanics