It's interesting that your wife doesn't choose to practice because of the perceived lack of femininity on the part of the women. I find many women in my dojo to be feminine, and these women are high ranking and have been practicing for years. These woman are petite and graceful yet their technique powerful. I guess I would like to know her definition of femininity. Aikido can be rather graceful and I have always viewed it to be a martial art that doesn't take this away from a woman.
I come from a dojo as well that has both male and female sensei, a husband/wife team as a matter of fact. He's 6th dan and she's 5th dan. Penny really prefers to emphasize the larger circular movements found in aikido. But I caution anyone from calling her a "flower"