She was attacked while she was sound asleep. What chance would she have had to retreive a gun and then center a few shots with those monsters all over her?
I suspect if it were a revolver and she could get to it she could have easily shot them with one hand as close as they were. The shot didn’t have to be centered if the dog is on top of you anywhere will do and even the noice might cause them to quit, but a shot anywhere would have helped.
I might be reading between the lines and getting it wrong, but I suspect that her Jack Russell intervened and while the Pits were attacking him, she escaped. That would mean she’d have enough time to pull a gun out and kill them . . . . if she were a good shot with nerves of steel (to shoot toward her own dog without hitting him.)