Hmmm a .38
If I was there and knowing that I wouldn’t need to carry concealed, I would have the largest caliber possible that I felt I could comfortably fire. Maybe in her case that is a .38 revolver. But how about going up a notch to .357 (or at least .38+p+), just make sure the revolver is rated for that.
I agree. Inside the store there is no need for concealment. I'd say a .38 caliber is OK. The cops used to carry that, before they all went to 9mm. However, I'd want more than 6 shots available. That's why I prefer semi-autos. Even a Browning Hi-Power gives you twice the number of shots as does a revolver, and it's a very easy gun to shoot accurately. Other guns give you even more rounds than a Hi-Power. Worth it, in my opinion.