The nice thing is I'll be making some powderpuff practice reloads so whatever she does get, it won't beat up her size zero hands.
Recoil sensitivity isn't really related to the size of one's hands, based on my own observations. I was at the range with a cute, petite 20-something girl from Great Britain a few lanes down from me. She couldn't have been more than 5'2" and 100 lbs. She was shooting various handguns with a friend (a US resident) and she was jumping up and down giggling with joy after firing .44 Magnum through his Ruger Redhawk. I think she went through a whole 50 round box of that high kicking WWB mag ammo with narry a complaint (darn good shot too).
OTH, my dad (6'5" and 230 lbs) couldn't stand the recoil of my .38 642 the first time he fired it (he has since changed is hand grip, and now owns a loves a 442 of his own).
As for trying guns, just be sure to differentiate the guns as much as possible, starting at generally the lowest recoil and work your way up, using a mix of revolvers an autos. I agree, it isn't realistic to try everything, but at least that would give you some good data points to narrow in on something specific.
My mother, who as pretty bad arthritis in her hands, settled on a .22 Hi Standard Supermatic Citation for home protection. The arthritis makes it painful to shoot anything else with any regularity, though she can manage a 4" steel .38 shooting light wadcutters for a few cylinders full. She is thinking about getting her carry permit, and she is considering a Ruger SR-22 for carry. Lightweight, easy to retract the slide and very little recoil, it is probably the best choice for her. Either that or the Ruger LCR-22.
Though I don't carry a .22, and never would, for some it really is the best choice because it won't hurt to practice and become proficient. To me, that beats the .45 you left at home because it is too big, or the flyweight .357 that you DO carry but never shoot because it hurts too much.