Single mother Noriza A. Mansor gets only one day off a week from her job as a bedsheet promoter.

Most would use that day to rest, but she spends it looking after an old man she met by chance as he stood in a Toa Payoh supermarket soiled by his faeces.

Ms Noriza, 49, made headlines last October when she stepped forward to help Mr Tan Soy Yong, 76, who had soiled himself while buying groceries with his wife, who was in a wheelchair.

Others had recoiled from the old man and his stench. But Ms Noriza not only bought him new shorts but she even knelt to wipe the dried faeces off his legs - an act which moved a bystander to tears.

Since that day, she has made it a point to visit Mr Tan for at least six hours a week at his Potong Pasir three-room flat.

Mr Tan has lived there alone since the start of the year, when his wife, Madam Lee Bee Yian, also 76, was hospitalised for cancer.

During her visits, Ms Noriza cleans up Mr Tan, who cannot control his bowels, and washes his soiled laundry. She also mops the floor and tidies up the flat, while chatting brightly with him in a mix of Malay and Hokkien. Some days, she will accompany him to visit his wife in hospital. On other days, she will take him out in his wheelchair to the hawker centre to eat his favourite wonton noodles.

Said Ms Noriza: "I only wish I could see him more often. Sometimes if I finish work at 8pm, I will go to see him. But I don't always have the time."

She often works 12 hours a day, taking home around $2,000 a month. She has three sons and two daughters aged 11 to 26. Four of them still live with her.

Yet she has no qualms about making time for the old couple. "In my life, I am never tired," she said.

Mr Tan told her he has a son and a daughter, but Ms Noriza said that, according to social workers, the couple have no children. She thinks they have a niece and a nephew living in Singapore, but has been unable to contact them.

Ms Noriza believes Mr Tan was sent into her life by God, as she lost her parents when she was 21.

Her father succumbed to cancer and her mother wasted away in depression eight months later.

She said she treats the couple as "my own father and mother".

Mr Tan once asked her if she had a passport. "I said yes. He said when his wife is discharged, we can go on holiday together as a family."

She smiled wistfully. "I know this kind of thing is very hard, with their conditions. But of course I told him we would. He's so sweet."