I wouldn't carry a semi auto either for a defensive weapon against an angry black bear. Who cares if it has a hundred rounds in the clip you aint going to get off but two or three, if you're lucky, if the bear charges you. And if that's the case then a 40 or 45acp aint gonna do squat to him.

A revolver in 44 magnum or larger would definetly be my choice. Even a 357 will be a heck of a lot better than a semi auto. Barrel length would be 3 or 4 inches and no longer.

I would definetly look around for a revolver that fits nicely withing your (I mean your wifes) budget.

Something along the lines of this 629 stainless with a 3 inch barrel.