Well, the FIRST thought is not to shoot .380 ammo in either the SP-101 or the S&W equivalent. That wasn't a typo; you said ".380" twice!
Your wife may be confused about the right cartridges.
These guns use revolver ammunition called .38 Special or are chambered for the .357 Magnum round, which also allows using .38 Special as a lighter load for reasons too long for me to explain here.
Recoil with .357 loads in a gun that size is fierce, not for the casual or new shooter. Use them with 38 ammo unless you need the added power, as a hiker might in a trail gun worn in areas where cougars or bears might be a threat. There are self defense scenarios that might cause me to load .357 ammo in my SP-101, but home defense isn't one: the muzzle blast and noise indoors may harm your hearing!
To answer your specific question, the S&W equivalent is the model 60-15. I think -15 is current; there may be a later dash suffix with minor engineering changes.
Because the S&W is a little lighter than the SP-101 and has a cylinder release more likely to cut your thumb on recoil, I prefer the Ruger in this size gun, chambered in .357. I also STRONGLY suggest the three-inch barrel option, which gives desirable extraction and increased velocity and control benefits.
I DO NOT advocate the spurless hammer. That is a specialty option for those who really want it, but it is less safe, I think, and precludes cocking the hammer for more precise shooting at longer ranges.
If the lady wants a lighter gun, she will pay for it in increased recoil, especially when firing the Plus P higher velocity .38 ammo. I think the answer is to buy an older Model 60 snub in .38 Special caliber, before they cheapened the line with MIM parts and added a lock that we aren't supposed to discuss here. If you want a new gun, and you may, given your lack of firearms knowledge, I'd totally buy the Ruger, despite it usually having a heavier trigger pull. I own both the Ruger and an earlier .38 Model 60-4, both with three-inch full lug barrels. I think the S&W platform is too much of a good thing when chambered for .357 ammo.
If a snub is required, the SP-101 is heavy for its size, but kicks less. It is durable; people often say that it is built like an Abrams tank. Ditto for the larger GP-100, a full size .357.
The light alloy snub guns kick like a mule with effective ammo. They carry easy and shoot rough.
A lot more research needs to precede your wife's gun purchase and she needs to learn for sure which ammo goes in which gun. Absolutely!
Others will voice other opinions. I think mine are the basics and need to be heeded. Good luck with your final purchase decision.
