For an introduction to guns of any type - a women's only class gives the ladies a chance to work with an unfamiliar "machine" in an uncompetetive atmosphere. My wife volunteers with our gun club to assist with the women's class.
The overwhelming concensus is that the women's class is a success because it gives the class a chance to see other women who own guns, can handle a variety of guns, and can shoot competently. They also like it because they're not being compared to men who are larger, stronger, more agressive etc.
The interesting outcome of this, is many of the women have started shooting action pistol, and don't mind competing once they feel comfortable handling guns and shooting.
Using the women only format, the Women's Introduction to Pistols has become so popular that it is booked nearly a year in advance. The course is given twice a year, and there's a waiting list for each class.