It's obvious to her that he has his hands full with the child screaming for sweets in the sweet aisle, biscuits in the biscuit aisle; and for fruit, cereal and pop in the other aisles.
Meanwhile, Gramps is working his way around, saying in a controlled voice, "Easy, William, we won't be long . . . easy, boy."
Another outburst, and she hears the granddad calmly say, "It's okay, William, just a couple more minutes and we'll be out of here. Hang in there, boy."
At the checkout, the little terror is throwing items out of the buggy, and Gramps says again in a controlled voice, "William, William, relax buddy, don't get upset. We'll be home in five minutes; stay cool, William."
Very impressed, the woman goes outside where the grandfather is loading his groceries and the boy into the car.
She said to the elderly gentleman, "It's none of my business, but you were amazing in there. I don't know how you did it. That whole time, you kept your composure, and no matter how loud and disruptive he got, you just calmly kept saying things would be okay. William is very lucky to have you as his grandpa."
"Thanks, lady," said the grandfather, "but I'm William ..
.. the little b****d's name is Kevin, and I'm gonna kick the little sh*t's ass when we get home!"