This may sound dumb, but while a hand gun certainly is a fine defense weapon, even under stress I would think it damn hard to forget where the shotgun is. It is that big black thing leaning against the bedroom wall.
As for felt recoil and fit, I could be persuaded to pick up something like a 3901 20 gauge for the women to share. The one time to date that they came to the range with me I got my wife to take 3 shots with one and my daughter finished off the box.
Another option is to put one of those tactical KnoX adjustable stocks on it, and I can't do it to my 870. To some it is just an ugly black gun, but to me its my first shotgun (since my youth and who can remember that far back).