Our monthly NRA Basic Handgun classes run between 20% and 50% women. We have three female instructors (all NRA certified and one also POST certified) in our group. We also try to maintain a 1:2 to 1:3 instructor to student ratio.
We find that on one hand women make better students because they actually listen and don't carry a bunch of gender related baggage ("I'm a guy so I automatically know about guns.").
On the other hand, many of our woman students have what appears to be a socially conditioned fear of guns, and that needs to be appropriately channeled. We don't want anyone to entirely lose the perspective that guns can be dangerous. We want them to come to understand that even though guns can be dangerous, one can with knowledge mange them safely. Patient, personalized instruction, as well as the "role-models" of women instructors, help a good deal.
Women also seem to benefit from more individual help with the mechanical aspects of gun handling. They are sometimes less mechanically inclined. They also sometimes have more difficulty managing the slides on semi-autos (but actually a lot of the guys in our classes do too).
When we have a chance to talk with some of our women students after the class, they generally say that before coming to class they were worried that they be patronized or talked down to, and they were concerned that the whole thing would be too "macho." We've worked hard to avoid those possible pitfalls. And a women only class would go far towards dispelling those concerns going in.
"It is long been a principle of ours that one is no more armed because he has possession of a firearm than he is a musician because he owns a piano. There is no point in having a gun if you are not capable of using it skillfully." -- Jeff Cooper