Just a few quick thoughts:
1) There is nothing inherently masculine or unfeminine about shooting. Please encourage the women in your life to try shooting. They may find an activity that they enjoy and that could prove very useful. To that end, there is a new annual event that I wholeheartedly support and endorse. It's national Take Your Daughter to the Range Day. Deets here. If I had a daughter that this was appropriate for, I'd surely be taking here. The blogger linked to is a fairly new female shooter and has some excellent thoughts on firearms, defense and being a female shooter.
2) The best gun for a woman is the one she likes to shoot. Unless she's planing on carting about inside of, or operating with her lady bits, her plumbing is perfectly irrelevant. Women have sufficient strength, intelligence and mechanical aptitude to operate and maintain any modern duty pistol or revolver. Breda (sadly no longer blogging but has an excellent archive) has gone to great lengths over this.
3) Manufacturers-talk to the ladies to find out what they want. Don't just slap a pink grip on something, call it "Lady Blastomatic" and feel like you've successfully reached out. Miguel has some thoughts here.