...her arthritis and my 642 didn't mesh...
Didn't mesh how, recoil or trigger pull?
If it's recoil, either load the current gun with factory 148gr wadcutters or go with an all steel J-frame and that load.
If it's trigger pull (hand strength) there's going to be a problem manipulating the slide on a semiauto without knowing a trick or two, and a lot of DA 380's have J-frame-like trigger pulls to boot.
Beretta made a DA 380 with the pop-up barrel like the Jetfire (I don't recall the model number) and a nice pull that might work, but it's about PPK/SIG 230 sized. If the size (and price) isn't a problem this would be my first choice.
Another alternative would be a single action like the Colt Mustang or SIG P238. The trigger pull would be easier, though there is still the problem with slide manipulation.
The same goes for the Kahr P/CM 380. Nice trigger, but tough slide and the need for a firm grip to ensure reliable functioning could be a problem.
If it's small you want, the Magnum Research Micro Desert Eagle is smaller than everything but the Seecamp, it's all metal (if that matters to you) and the gas-retarded blow back action means the slide will be a
little easier to work, but again the trigger is J-frame like.
Good luck with your Quest.