Kudos for her and her son who didn't just give her a weapon. He obviously educated her and gave her the confidence to use only enough force to minimize the situation. This is a good story. Had she shot him in the back out of fear, this would have hurt the cause.
Never bring a knife to a gun fight. It does remind me of the movie The Untouchables..."They pull a knife, you pull a gun. He sends one of yours to the hospital, you send one of his to the morgue. *That's* the *Chicago* way!"