An energetic grandmother named Carol Flynn decided to step in and help a thrifty young mother who had been ‘counting her pennies' at the local Walmart store in Sioux Falls, South Dakota.

It was a random act of kindness, a private moment between the two women, but a watching stranger caught the scene on video and posted it online to inspire others.

On Sunday night, she saw a young mom remove three of the four large boxes of diapers in her shopping cart and put them aside because the store wouldn't price-match the items on more than one item.

So Flynn walked over and placed the three 148-count packs of Pampers back in her cart and insisted on paying for them.

(WATCH the video below or READ the story from TODAY)