Make sure you go with your husband shopping for the gun. It needs to feel comfortable in your hands. We have a gun that is a bit larger than I feel comfortable holding. The grip is a bit too large for me and the trigger is almost a stretch for my small fingers. Keep things like that in mind. You want a gun that doesn't feel too heavy and that has a good grip for you. IF you ever needed to use it in self defence you don't want someone to easily be able to take it away from you because you can't get a good grip on it.
My husband says the following because he knows his stuff:
Keep it light; keep the trigger pull smooth & crisp to make sure you can pull the trigger, he says a double action. He would go with a stainless steel finish that way you don't have to worry about smudges or nicks. He doesn't think a 9mm is the best choice if you are not already familiar with guns. If you insist on a semi-automatic he definitely prefers something that has very little feeding problems and very good accuracy like a Sig or Beretta which are easy to take down and clean, few parts to worry with. He would advise against a Glock or an M&P because although some people consider those guns perfection they have been known to blow up in people's hands.
More importantly than the gun is the ammo. Pick an ammo that is clean burning, that doesn't dirty up the gun too bad, that doesn't jam the gun, cycles well. As far as caliber goes, 40 caliber you can't go wrong. With a 9mm you have to be a lot more finicky about your selection of ammo. The design of a 9 mm round is prone to hollow point clogging, meaning the bullet won't open up when it hits the target, and it has built a nasty reputation as over penetrating.
For the Sig look at a P228 and for the Beretta most any model they have will do.
He thinks you will be better off with a revolver overall because they are easier to learn, easier to clean, less to have to worry about, no jamming, etc.
Please let me know if you have any more questions. I hope I didn't just over load you!
He took me on my first shooting range trip last year to teach me about our gun. It was very interesting, especially seeing how the different bullets shot. We are looking at getting me a smaller gun this year that I can handle better. I want to do more target shooting.