Being as you're in the epicentre of all this "no guns" nonsense (Sacramento,) I'd have to temper my suggestions. Also, since your wife my end up carrying for work, it would be useful to know if it's going to issue or a personal piece, and what's going to be issued, if anything.
Considering I've shot damn near everything out there, I fell a bit qualified...
First, keep the Smith. Even neglecting value, it's hard to get a good .22 anymore, and it's a LOT cheaper to practise with a .22 than with a full calibre. You can keep basic marksmanship going that way.
Second, how large are your hands, and your wife's in relation to yours? Important question - if you can't get a good grip on your sidearm, you won't feel comfortable shooting it, and confidence will decline slightly. Maybe not enough to notice, but enough to cause trouble when you really need the thing.
Third - forearms? More for your wife than yourself - but forearm strength helps to handle recoil with any wheelgun, and most autos like to be held nice and solid to load that follow-up shot. Limp-wristing an auto is a great way to get a jam.
Especially for home protection, I'd not get a 9m/m - too much danger of overpenetration and secondary injury. Better with a .40 or a .45 - what platform depends on what you feel comfortable with. While I grant that I've got relatively small hands, I've never felt comfortable with a "double-stack" anything (ammo forms two stacks in the magazine, staggered,) for daily use. Oh, I can shoot them - I can shoot damn near anything I can get my hands around - but I just don't "feel right" with the double stack. Some .40's and most .45's come in single stacks, which lets the thing grow out of my fist, rather than my holding onto it.
If you'd like to get some advice, do feel free to PM me - answer the questions I've posed, and expect more. I never really did believe in "issue" firearms - it may make sense from the point of view of accounting - and logistical train - but if I'm going to have people hang their hopes on a sidearm, I want it to be one they're comfortable with - and that means matching the sidearm to the person...
5-90