A small revolver is not a bad choice. You should take said ladies to the LGS and have them handle and manipulate a variety of suitable pistols/revolvers.
My wife prefers small autos. She picked out both a Kahr CW9 and a S&W Shield.
The ability to rack the slide and handle the trigger pull is the limiting factor for most women. Took a friend and his wife out shooting recently, she wanted a carry piece. She shot several of my compact pistols and ended up picking herself out a G43 at her LGS.
