I will add my welcome aboard and also suggest that a .357 magnum loaded with .38 special is a good choice. It is what my lady uses, and I have no issues with her choice. I should also add that I carried a .357 magnum for many years as a LEO, and it worked every time.

BUT....a pistol and a shotgun are not mutually exclusive. If there are two of you, two firearms might be handy. And a pistol and a shotgun compliment each other well. That is why the combination has been used in police vehicles since they were invented.

But, no matter what you finally decide, please get quality instruction (especially shoot/don't shoot instruction), and practice frequently. If you ever need to use a firearm in anger, the life you save will be your own, and probably your loved ones as well.