Robyn Ayres of Raymond, N.H., told ABC News that when she went to make a small payment toward her $283 worth of layaway items, the Walmart employee said she could keep her money.
"He said, 'A woman saw you and she said wanted to pay a portion of your bill,' and I just started crying," Ayres said. "She paid more than half of our bill. It was crazy."
The mother of two said she was left with a balance of $130 and an anonymous note. The handwritten message on the back of Ayres' receipt said, "I hope you and your family have a Merry Christmas. The lord is always with you! Have a blessed Holiday Season!"
Ayres said she and her husband are "grateful" for the stranger's generosity, and their two sons Griffin, 11, and Ryder, 3, will be overjoyed on Christmas.
"Within the last year, we had to put our family dog to sleep and had to pay to do that," Ayres said. "We've had several financial setbacks. Our stove busted on Thanksgiving so we didn't have that and it just pushes you back. We almost lost our house a few years ago and just to see someone doing this just makes us so happy."
Ayres said the anonymous woman helped her pay for Xbox games, a Lightning McQueen toy, and other gifts.
"I wish there was a way to thank the woman," Ayres said. "I would just say thank you for restoring our faith in humanity in a time that is pretty much dark."
ABC News reached out to Walmart for comment.