For protection against a bear, and givent hat she already has experience with a .38, and probably has accessories for the .38, I would go with a .357 magnum. When I hunt black bears, it is usually with a 12 gauge, using Hornady 300gr SST slugs, and I back that up with my Ruger SP101 5 shot .357 magnum with a 3in barrel. Relaible, accurate easily out to 50 yards for a bear sized target, and it has more than enough pop to get them job done.
But where we hunt in Arizona most of the time, our bigger concern are the two legged predators, like the drug runners, and for that I want something a little more "tactical", but I often hunt areas where run ins with mountain lions are a real possibility, so I pack my Glock 22 .40 cal. It has high capacity, it is easy to use, and will take a lot of abuse and still go bang. I know that the .357 sig is getting a lot of press lately becuase of it's balistics, but I want to use something that has a longer history in self defense, so I stick with the .40 cal
Good luck.