While a manufacturer may be able to point to measurements of recoil forces, and call something "low recoil", the way the recoil is felt by people is still pretty subjective.
I've listened to some shotgun shooters express that the "low recoil" buckshot they're required to shoot (listed as having up to 40% less recoil than standard buckshot) still has a lot of recoil. I imagine if I gave them some Magnum loads to try, they might have a different perspective ... but that doesn't mean they'll suddenly be able to use the low recoil buckshot any better.
I've used some advertised "low recoil" .357 Magnum in one of my M&P 340's, and it still hammers the palm of my hand and snaps the little gun upward hard enough to batter the knuckle of my index finger. If it's "low recoil", you could've fooled me.
Is your wife shooting a 5-shot snub? Is it an Airweight (or lighter) or all-steel? Going from an Airweight to steel helps a lot of folks quite a bit. Going from J-frame to a K-frame helps even more.
I've listened to one LE trainer discuss how an agency he was helping choose duty ammo for their authorized J-frames (secondary weapons) were looking at issuing 148gr target wadcutters, instead of one of the "better performing" (in scientific gel testing) modern +P JHP's. Why? Because they saw an immediate and significant improvement in accuracy and controllability when testing officers.
I own a very nice M37-2 which only sees standard pressure loads. I carry one or another of the most easily found 110gr standard pressure JHP's in my area, which are the W-W 110gr STHP and the Fed 110gr Hydra-Shok. A bit more felt recoil (to me) than the 148gr target WC, but still quite controllable (for me). If I couldn't find a standard pressure JHP which might expand (providing the potential for larger cutting, tearing effect), I'd revert to either the standard pressure 158gr LSWC or 148gr WC. Anything other than 158gr LRN or 130gr Ball.
There's always a potential for trade-off's that fall to one side or the other of line separating the "advantage/disadvantage" columns when you're looking at compromises.
If you've already decided to use a small, lightweight revolver, then you try to find ammunition that will yield the amount of felt recoil force that she considers tolerable, and which permits good accuracy. If you can go to a larger, heavier revolver? Well, that might open some doors to harder recoiling .38 Spl +P loads that are observed to potentially be "more effective", while letting the increased revolver weight mitigate the felt recoil.
Of course, using soft, all-lead loads means a little more effort is going to be involved in keeping the cylinder charges holes and barrel clean of lead buildup.
TANSTAAFL, always. (There Ain't No Such Thing As A Free Lunch)
She's got to
consistently hit her intended target. Excessive felt recoil that causes flinching, especially under stress, isn't going to exactly help, right?
Using ammunition that maximizes her ability to shoot without flinching, accurately, is better than a walloping load that makes her flinch and miss.
Just my thoughts, anyway.