"When she came in, she told me that someone had left the shopping with a note. When I read the note I teared up. I was shocked. It was totally unexpected."
The rest of the note read "Hi Emma, I'm doing food drops in the community, and someone has put your name forward to receive one. I'm also doing kids packed lunches Mon-Fri.
"If you don't want to receive the kid's lunches, just send me a message. Otherwise, I'll drop them between 10.30 and 12pm.
"No need to come to the door, I will knock, drop and leave. A gift from our family to yours."
The act of kindness comes after the UK government refused to extend free school meals into half term, which reportedly left many families struggling to make ends meet.
"I think the government have made the wrong decision as there are more families in a worse situation than we are, and they could really do with the help," Frost said.
The unexpected surprise prompted mixed reactions from her children, aged between 11 months and 16.
Frost thanked the stranger for the gesture which made her day.
"I would like to say thank you from the bottom of my heart," she said. "On a day where I was struggling mentally, you brightened it up. It is very much appreciated and it shows there are still some people sharing their humanity around."