Hello! I find this thread particularly interesting, due to my own very limited knowledge of Aikido.
Most of my training in the fighting arts comes from the Army, and in my experience, size, speed and strength are critical in either avoiding or winning a fight. When I started Aikido a bit over a month ago, the member who worked with me most was (and still is) Jill, our senior student: a 1st-Kyu of middle years and all of 120 pounds soaking wet. It took me all of 5 seconds to realize how wrong I was about strength, size and speed as I wound up staring at the ceiling time and again.
We have a few students at the Dojo; she is the only woman as of this writing, she is also possibly the most highly thought of person at the Dojo - at least, I think so.
Of all the Martial Arts, it seems to me that Aikido is perfect for women in today's day and age - a 'fighting' skill based on relaxation, calmness and efficiency. So much of it seems perfectly adapted to 'domestic' situations and other areas in which a woman may find herself in trouble.
Due to the low number of students at our Dojo, I've offered my skills as a recruiter in order to help bring in students. The hook I'm planning on using is the 100% demographic of Aikido - in other words, that anyone, regardless of age or sex can do it.
Therefore, I personally think that women should be encouraged to join Aikido - not only for the exercize, but for the factors of defence, safety and confidence it can provide. Not just women actively looking for a martial art - any woman at all. (I yap on incessantly about Aikido now; trying to recruit just about everyone I meet. hee hee!) A 50-year-old librarian isn't going to turn in to Stephen Segal, she WILL NOT become any less attractive (quite the opposite; most probably, moreso.) but she will gain benefits too numerous to mention.
I hope this is not just rambling, that it can actually help this thread.