Herd a similar story a couple years back, only I think grandma had a semi-auto in the glove box, a snub-nosed revolver in her handbag and a 12ga pump in the trunk.
I'm sure that there are some seniors who do go well armed but I doubt that this particular account ever really happened as posted. When granny was initially asked if she had any weapons in the vehicle she likely would have told the LEO about all of them and not made him ask repeatedly if there were others.
It's also unlikely that the LEO would have kept asking. For one thing the question is usually stated "Do you have any weapons (plural) in the vehicle with you now?" At least that's been my personal experience.