This comes up all the time, and the answer is it depends. Someone with wrist issues is not the same as someone with finger issues is not the same as someone with both.
4" .38 revolvers, larger .380 pistols, that's where I'd start. Something that fits her hand, remember grips can be swapped out, and remember that ammo selection can be tailored a bit. 110 gr .38 va 158 gr, etc will have less kick then heavier loads. They may give up a bit in wounding ballistics, but if the trade off is it functions and can be shot comfortably, that's likely worth it when these types of decisions must be made.
Rimfire LCRs are probably not a good option. The trigger is much heavier than the centerfire versions because the spring weight is much heavier to help ensure ignition.
I did not know that the triggers wet different. I read that on on a gun review but those are often full of spit. But the trigger is different then the centerfie. That could indeed be an issue. I guess that means a Smith Kit gun then. I have a friend with a loved on Smith 317 snubby, it is a sweet little gun.