I have owned the M&P Shield in 9mm for a couple of months now and put about 150 rounds through it. For some lucky people like me, the 18 degree grip of the M&P line makes for more natural off-hand shooting, desirable of course for a gun marketed for self-defense. While it's similar in overall dimensions to the Glock 42 (.380), it's weight no doubt makes recoil quite manageable.

I very much like this weapon, but there are some annoying properties with mine, and not everyone may experience this with theirs.

A full magazine requires a pretty brisk tap to seat properly. This seems less of a problem when the slide is in lock-back position.

The slide is a little hard to draw back, and does take a committed effort to get it into lock-back position.

The front sights on mine are not centered, and it appears to be impossible for the average gun-owner to adjust them. I tried both adjusting and removing (in the recommended direction) and bent a brass punch in the process. That sight isn't going anywhere without a drift tool or a visit to a gunsmith.

All that said, adjusting my aim provides fairly consistent 2 inch grouping at 25 feet. Still haven't decided if I want to send it off or just spend the money on a local smith to keep from being without it for two or three weeks.

I think if you get one with correctly centered sights, and your wife doesn't have complaints about the weight (19 oz unloaded) I think she would find it easy and comfortable to shoot, and it's good to have the best fire power that she can manage. She might also like having the Pearce grip extension, and the Pachmayr grip glove.

Good luck and always be safe.