Lewis pocketed pounds 18,000 after winning Britain's first medal in the World Championships while her mother, Joan, watched from the stands.
The 24-year-old from Wolverhampton, who never knew her father, knows it was the series of low-paying jobs taken by her mother that provided a financial bedrock in the early years of her career.
Now it is pay-back time for Lewis who, when asked what she would do with her prize money, said: "I can help my mother pay off the mortgage. That would be nice.
"She has always been so strong. She's my best friend as well as biggest supporter. It's good to know that she is there in the stands watching me."
Lewis' medal exploits have been carefully documented in scrapbooks by her proud mother. "Sometimes she will get them out and say, `Did my little Denise do that'," the heptathlete said.