Paying it forward: Shopper, 73, buys $120 worth of diapers for cash-strapped new mom next to her in the Walmart queue

When a young mom struggling to pay for diapers held up the queue at Walmart, Carol Flynn didn't tell her off - she pulled out her credit card and paid for them. 

Now the 73-year-old has become an internet sensation after a shopper who filmed her kind deed posted it to Facebook.

'Diapers are for babies and babies are on my heart,' Flynn told ABC News. 'We’re always concerned about moms and healthy babies.'

Generous: Shopper Carol Flynn, 73, paid for four boxes of diapers for young mom Katie Kanefke at a South Dakota Walmart on Sunday

Kindhearted: Carolyn Flynn, 73, put an arm around young mother Katie Kanefke at a South Dakota Walmart on Sunday night after paying for her diapers purchase 

Heartwarming moment woman pays for stranger's diapers

According to Argus Leader, Flynn was shopping at Walmart in Sioux Falls, South Dakota when she noticed a cash-strapped mom couldn't afford to pay for four boxes of diapers.

The young mom, Katie Kanefke, put aside three boxes of Pampers when the cashier declined to match a competing store's lower price.

That's when Flynn stepped in and helped Kanefke out.

'You can't take it with you,' Flynn told Argus Leader. 'I just think we should do things like that. That's kind of my thinking.'

For Kanefke, a stranger's random act of kindness is something she will never forget.

Kanefke and her husband Jimmy support their four-month-old son Marcus on a single income, so are forced to stick to a budget.

'I couldn't believe it. I was shocked. I kept saying thank you and God bless you,' the stay-at-home mom said.

'Then I walked out in the parking lot and started crying. It just hit me. It was an awesome statement of what God's love does.

'If you ever needed a sign or act that shows God cares for his people and provides for them," says Kanefke, "this is it''.'

Katie Kanefke

Grateful: Katie Kanefke (right) said she couldn't believe it when stranger Carol Flynn bought four boxed of diapers for her four-month-old son Marcus (left)

Single income family: Katie Kanefke (left) is a stay-at-home mom and her husband Jimmy (right) works

Carol Flynn and Jason Yoshino

Heartwarming: Shopper Jason Yoshino (right) filmed Carol Flynn (left) generously buying four boxes of diapers for a struggling mother in Walmart

However Kanefke is not the only person moved by Flynn's kind deed.

The shopper who filmed the exchange, Jason Yoshino, shared the clip on Facebook to inspire others. It has been liked more than 23,000 times and shared more than 6,000 times.

'Me and my wife were stunned. You hear about those things, but you don't see them in real life,' he said.

'Everybody has a camera phone, and they're recording everything. (Still), you don't see something like that every day in life.

'It definitely touched a chord with me. I always try to inspire others, and I'm a huge advocate of uplifting and changing the world. I'll never forget it, to be honest with you.'

Scene: Carol Flynn kindly bought Katie Kanefke four boxes of diapers from Walmart on S Louise Ave in Sioux Falls, South Dakota (pictured)

DM