I suspect that Jammer-Six's class is all about gun fighting, and Kathy's class is about something else entirely. The gun fighting class may not gain much by being female-only. But Kathy's class probably deals with philosophy, mindset, and the gamut of all kinds of issues involved in carrying a gun and being prepared to use it. Thus, Kathy's class stands to benefit a great deal by being a woman-focused class.
Another point which is unrelated: In my experience, the differences among men (or among women) are greater than the differences between the typical man and the typical woman. Teaching a class for women requires making assumptions that women are different than men (apart from obvious physical differences)... and on average, woman are different than men, but the differences from one woman to another may be greater than the male-female differences.
Macho behavior, or bragging/posturing will annoy a certain type of man just as much as it will many women. And I know several women who avoid social activity that is "woman-centric" because the typical woman just drives them nuts.
I think it might be just as valid (or more valid) to separate training classes based on personality type. Introverts on Mondays and Wednesdays, Extroverts on Tuesdays and Thursdays... Or perhaps segregate the training based on age groups... After all, the "millennials" tend to drive the gen-x'ers nuts, and the baby-boomers are quite insufferable (just kidding
- its humor ). But the point is that 20-somethings will have a different learning style than 60-somethings... These differences might be more important than gender. I am not offering this as a practical suggestion, but hypothetically it might be better than male-female segregation.
Despite what I have written, I think a woman-only firearms training class has many benefits, and clearly this is what many women want.