I agree with ipsc here.

Never ever will I again assume that my wife enjoys the complexities and inner workings of semi-auto firearms, or that I have the slightest idea what's going to fit her hand the best, let alone manipulate effectively - especially in a crisis situation.

Revolvers are the simplest to operate, and (in my experience) the least likely to result in negligent discharges. Of course, you could put a clearing barrel at each of the doors into your housejust like they do at all the KBR DFACs.....? (j/k).

By all means, let her handle a few of them, too.If she feelslike the thing is too big for her, it will be - regardless of the caliber - and her confidence level will suffer accordingly.