I hope someone here has both, or has fired both.

I need a hammerless, light, small 22lr revolver for an elderly lady. I am not asking which you think is the better revolver, but only which has the better trigger for an elderly lady with limited hand strength.

By "better" I do not mean the overall quality of the trigger, but simply which will likely be easier for her to pull. Of course, smoothness helps a trigger feel lighter so it is not just about weight of pull.

These days there are are not a lot of choices in LGS' here for any handguns for her to actually handle, and definitely not those two. I know, a centerfire revolver will have a lighter trigger but she will not consider anything more powerful than the 22lr.

I have had her dry fire my J frame centerfire and she has no trouble with that. I also had her dry fire my LCRx22lr, and it was much heavier but she can handle it. I don't think she found it easy though. I would like to also consider the 43C for her but don't have one for her to try.

All rimfire revolvers have heavy triggers, but does one of these two have an easier trigger than the other?

It's a tough call, because you're only likely to experience 'examples of one'.
Since she's tried your Ruger, and found it wanting....I'd give the 43C a shot.
No S&W prejudice, just my gut having owned several rimfire J-frames, and dry-firing more than several examples of the LCR rimfire.

You're more likely to have a more manageable, box-stock, trigger with the Smith. Plus, endless grip selection in order to position her hand for the best leverage. You can buy a spring-reduction kit for the J-frame from many sources. EVERY gunsmith can 'tune' a J-frame, LOL.

So, you have options that simply dont exist with the LCR.

Not exactly answering your question, but...

When I bought my 43C new a dozen years ago, the trigger pull was horrendously stiff. "Everyone" told me that was because the hammer spring needs to be super strong to ignite rimfire primers.
I replaced the rebound spring with a 15# Wolf, and the hammer spring with a 8.5 lb Wolf, which is supposed to equal the standard spring in the centerfire J-frames. The gun still functions normally and the trigger pull is noticeably lighter.
Do lots of testing with the appropriate ammo before turning her loose with this setup.

I have fired both. Rented the LCR and purchased the 43c as a trainer for my 642 and 640 pro. Contrary to what I was led to expect, the trigger on my purchased new 43c is really not any different than the trigger on my new center fire J frames. When I first tried it, I was worried that it was sprung too lightly and would be prone to light strikes. This has not been the case. I really enjoy shooting it and this has allowed me to improve my proficiency with my 640 and 642 despite the ammo shortage. My 642 has had a trigger job/spring change and about 1000 rounds through it, my 640 has had 2000 plus rounds through it and my 43c has had 1500 rounds through it. The 43c really improved at 500 rounds. All three feel about the same. I am sure that some will say that I got a good one. My recommendation would be to buy the 43c, if you can get it, and then break it in for your elderly lady friend by by putting at least 500 rounds through it for her.

Thanks very much for the help guys.