A .38 Special revolver, they don't jamb, your hands may not be strong enough to rack a semi-automatic, and they won't get stronger as you get older. Don't let anyone sell you a revolver without a full hammer. if your hands are semi-arthritic you may have trouble pulling the trigger on a revolver with a shrouded hammer, if you have trouble cocking the hammer with your thumb, you can use your other hand.
Thanks c-b. My husband just got a semi-automatic and I realized today I was unable to rack it without difficulty. Hence the reason for research! Appreciate the insight :)
I think that c-b 1's reply is close, or maybe right on for you. My wife has arthritis (RA and OA) and osteoporosis. she carries a heavy (to reduce recoil) .357 magnum (S&W 686, 4" barrel) loaded with medium velocity .357 mag personal defense rounds. The revolver has had a trigger job by S&W, and it's great for her. I recommend a similar revolver, or maybe a .357 Magnum S&W Ladysmith model 65 3" barrel, a little bit lighter and smaller, and in any .357 Magnum you can choose to carry .38 Special lower recoiling less powerful ammo.
One possible exception to this would be the Ruger LCR. Through some ingenious design work, they have managed to make the trigger pull "feel" like single action, even though it's DAO. I was impressed when I checked one out recently. Considering getting one for my (and wifes') arthritic old hands.