I guess what this comes down to is being one of those people who sees their pet as a 'child'. I, being an admitted cat person, do not think I would EVER react to a threat against my cat, by placing my own self in harms way. If I had been carrying something of .357 or greater power, I might have used my firearm to protect my cat, but even then, in a neighborhood, I'm not sure I would have reacted violently to the bear.
But, if it grabbed one of my children, I could see myself reacting this way...whether it's a gun on my hip, a kershaw in my pocket, a rock I grab on the way there, OR my bare hands...you are going to do whatever it take to save your child.....and if she thinks of this dog this way, I can't fault her for her actions....I can maybe question placing that kind of value on a dog, but if she has already made that mental leap, then she did the right thing. Even better, she was lucky, and survived.