First is women’s hand strength which makes heavy guns and heavy triggers a complaint item. These make revolvers hard to really get mom interested.
I'd say it depends on the mom, and the pistol. Desire can overcome a number of physical difficulties, but not all of them, and physical difficulty can kill desire. You need to balance and adjust them to the shooter. There are "work arounds" for many things, but its much better to begin with a gun that fits the shooter's physical capabilities, rather than one they have to work at in order to learn to operate it.
For example, my mother was 4'10" (and a half, damnit!!) never weighed over 110lbs in her life, and wore a size 3.5 ring. My son's mother is 5'9" and weighs ..er..considerably more..
, and has a much larger hand size.
My Mom couldn't use any of the pocket autos, though the grip size was good for her, she couldn't rack the slide. (a combination of small gripping area and her small fingers and gripping strength). She could operate a Colt Government Model, and preferred Dad's .38 Super over his .45, but wasn't really crazy about either one. She could also shoot Dad's Highway Patrolman ,357, but not DA, too long a trigger reach combined with the pull weight and the overall size of the gun for her small hands.
Dad got her a Ruger Super Bearcat, and she loved it. She shot it a lot, and shot it well, to the point where she got the local nickname of "Annie Oakley". A small light gun that is shot well even in calibers sneered at for personal defense is a better choice than a bigger, more powerful gun that can't be handled well by the shooter.
Today, few consider the SA revolver to be a good choice for home defense, against guns that hold more rounds, and reload faster, but for something to use to target shoot, train a new shooter, and could be pressed into adequate defensive use in gravest extreme, but I don't think it is something to be completely ignored.
You have the simplicity and durability of the revolver, no long heavy DA trigger to master, it only works one way, no slide to rack, no magazine to ensure is fully seated, etc.
IN this case, its not intended to be a carry gun, nor a priority self defense gun, but a gun for target shooting /plinking that could be used defensively. SO, while a combat/duty style gun would do, perhaps its not necessary, and a more sporting type would serve better?
A Ruger SA in .357 (and there is even one that comes with a 9mm cylinder) gives a wide range of ammo choices, recoil and power levels from mild to wild, and ammo cost from about as cheap as it gets, on up to what ever you want to spend for premium...
Plus, there is also the possibility of them just liking to shoot it. This isn't a minor thing. Getting beginners (no matter their age) interested and enjoying shooting is a good thing, and a "light" gun helps with that. Even a .22LR is better than nothing, and when they get comfortable and enjoy shooting, that "only going to get one" might become "only going to get one more..." that "one more" being a more serious defensive pistol.
Just some things to consider. Might not be the right choice for you and yours, but something you could consider along with other things.