In the supermarket, she found herself following a grandfather - and his really badly behaved grandson who looked about three years old.
He obviously had his hands full because the boy was screaming for sweets, biscuits and fizzy drinks depending on what got his attention.
Meanwhile, the grandfather was concentrating on the job in hand, constantly speaking in a very calm voice
"Easy, William, we won't be long. take it easy, Boy."
Another outburst and she heard the grandfather quietly 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 menace was throwing items out of the trolley and the grandfather said again in a controlled voice
“William, William, relax man, don't get upset. We'll be home in five minutes. Stay cool, William."
Very impressed, when she went outside, she saw the grandfather loading the boy and, finally, his groceries into the car.
And she went up to him and said
"I know it's none of my business, so please excuse me saying this, but you were amazing in there. I don't know how you did it. You kept your composure and, no matter how loud and disruptive your grandson became, you just calmly kept saying things would be all right. William is very lucky to have you as his grandfather."
“Well, I am indeed his grandfather,” came the reply, “but actually it’s me that’s William. The little b******d inside there is called Patrick”
(Thanks again pat’n’sandy!)