Woman here. I generally don't like off-body carry but if it is what your wife wants to do that's fine as long as she is aware of the pros and cons of it. Most everything has pros and cons so we have to choose what works best for us personally. For some women that is the only way they are willing to carry. I understand because I'm just not going to wear a belt. I usually pocket carry when I carry.
What size and kind of purse is she willing to carry? Some women carry purses that will hold the kitchen sink but some, including me, won't. I like small purses so that would limit my choice of handguns if I purse carried. If your wife is willing to carry a large purse there are fewer limitations on the kind of handgun, although I'd think a larger heavier one would still be more problematic on a daily basis. (See Joe's shoulder comment above.) Also, if she has only certain brands of purses she'll carry, can she find one with a separate compartment for her handgun? Yes, a lot of us women care about such things.
One thing that is a MUST imho is that the handgun should always be in a totally separate, dedicated compartment of the purse with nothing else in it. I'd probably still want it in a thin holster. I'd also personally want either a manual safety or a fairly heavy trigger pull, as purses are subject to a lot of movement and going into and out of them frequently with a lot of other items shifting around adjacent to the handgun compartment. It's not like something in your waistband, on your ankle, or in your pocket that is basically left alone with no items near it. It's in a purse that sees a lot of "action" and has a lot of other, frequently used items in it.
My daughter used to carry one of the Springfield pistols in a holster in her purse. My daughter-in-law still carries a little M&P Bodyguard .380 in her purse, but she only carries small to medium sized purses, not the large ones, so it has to be something small for her, and she likes the gun.
I think it's a good choice, as it's hammer fired with a fairly heavy trigger pull and it also has a firm thumb safety for those who want to use one. The slide is fairly easy to rack compared to some pistols, but it's a tiny pistol which may not suit your wife. I pocket carry mine sometimes, in a thin holster with nothing else in that pocket.
Take the purse out of the equation. If her criteria are semi-auto, 9mm or 380, have her shoot a bunch of those and pick the one she does best with. Chances are it’ll work fine in a purse with only minor mods if that’s where she has to carry it.
I agree, with the caveat of the purse being large enough and having a totally separate dedicated compartment for the handgun and being one she's actually willing to use.
I totally agree that if she doesn't like the gun everything further is moot. It's going to take a combination of a handgun she's comfortable with using and then finding a purse that's suitable and one she is willing to carry.
I also think a small revolver isn't a bad purse carry choice because of the heavier trigger pull and compact size, but if she doesn't like a revolver, then that's out for her. She's really going to have to try things and find a combination of handgun/purse that works for her. Stating the obvious, I guess.
I'm sure there's something out there that will work for her, but it may take some looking to find them. I'd start with the handgun, keeping in the back of my mind it had to be workable in whatever kind of purse I like.