Accordingly, she has a Remington 870 and we are getting a small J frame revolver.
The 870 is the youth model (20 gauge and the stock is not as long as the regular model). It is very good (correct size, inexpensive, and she can handle the recoil). But being a pump, she has to practice so that she remembers to pump in a round after every shot.
Concerning the revolver, if you have small hands, then a J frame is the way to go. The J frame is a small frame for a Smith and Wesson revolver, but most other manufacturers have revolvers of the same size. My daughter shot my Smith and Wesson M38 revolver (J frame, aluminum frame, soft rubber grips, 38 special round) this weekend and liked it, but she is also going to look at some small Taurus revolvers. With pistols, it is very important that you find one that fits your hand, because if it does not fit properly, then you will have a more difficult time shooting it properly.
I can go on and on, but the the most the two important things are to get the gun you are comfortable with and practice. It is amazing how easy it is to miss, when you are not familiar with your gun.
I showed my arthritic father how to put his left hand on top of the slide, and then push the grip forward with the right hand. He cannot hold the gun with his left hand and pull back the slide with his right.
It’s simple, but it works.