Madam Lai Yau Kiew bears the scars - literally - of nearly four decades in the hawker business, but in all that time she has managed to keep the recipes to her wonton, dumpling and soya sauce chicken noodles a secret.
Two 15cm-long scars run down her knees. The 62-year old owner of Ji Ji Wanton Noodle Specialist went for a major knee operation in March because the cartilage around those joints was worn down from the long hours she spent on her feet.
Thick, varicose veins wrap around her feet - damaged by a frightening incident that saw her end up in hospital last year.
She told The Straits Times she had been talking to a fellow hawker outside her two adjacent stalls at Hong Lim Food Centre, when she felt the floor was sticky.
"I looked down, and saw blood the colour of pig's liver all over the floor - it was scary."
Her varicose veins had ruptured and the ensuing operation left her sapped of physical energy.
But her dedication to her stall remained. In the weeks following the operation, she would still go to the stall daily to watch her two children - Ms Jill Choong and Ms Kristen Choong, both in their 30s - hard at work.
These days, she still struggles to stand for long but helps out often while her daughters manage the day-to-day running of the stall.
The veteran hawker may soon be passing on her skills to someone outside the family, under a scheme launched last Monday to preserve Singapore's hawker heritage.
She will be a "Hawker Master Trainer" in the upcoming Hawker Master Trainer Pilot Programme - a collaboration between the Singapore Workforce Development Agency and National Environment Agency, supported by real estate firm Knight Frank and The Business Times.
"Being a hawker is really tough," said Madam Lai. "I will need to see if they can withstand the long hours, the pace of the work and the cauldron heat."
Her stall was set up in 1965 by her parents and the only child would help out every day after school. "I used my eyes to learn," she said.
When her father died 12 years later from tuberculosis, Madam Lai felt compelled to take over.
She moved away from her father's use of pre-made sauces and char siew and started making and roasting her own. She even got a supplier to manufacture a special type of noodle for her.
Today, these unique traditions continue in the hands of her daughters. The stall boasts springy noodles, fragrant sauces and tender char siew.
Both women started helping out at the stall from the time they were eight, learning how to wrap wantons and dumplings.
Madam Lai says her younger daughter Jill has "nimble fingers", and has picked up her skills.
The younger Ms Choong says her father's death in 1997 awoke her to the urgency of mastering her mother's skills. "Before that, I was very lazy and didn't want to learn," she said. "Besides, the hours are so long, it's scary."
Their mother's varicose vein ordeal impacted both sisters.
"I realised it was now up to me," said Ms Jill Choong. "I had a responsibility not to let Mama down. I didn't want customers to say the food tasted different without her around."
Ms Kristen Choong also decided to work at the stall full time after running her own import and export business.
Both sisters have inherited their mother's passion and discipline. Their days begin at 3am with food preparation, then it is non-stop from 7am, when the stall opens, to 7pm. By the time they clean the stall and pack up, it is 9pm.
This is their routine, six days a week. It was only after Madam Lai's hospitalisations that they started having a rest day. The last time any of them went on a holiday was 16 years ago.
Ms Kristen Choong said: "This is the spirit of commitment and excellence Mama had for her food, and we want to continue it."
Madam Lai says she "feels bad" whenever they close for a rest day. "I don't like people to feel disappointed when they come to buy our food and we're not open."
Customers make their day. "What keeps me going is when people tell me they like what I cook," said Ms Jill Choong.
Like their mother, the sisters bear many scars of the trade. Marks on their arms point to the countless times they have been scalded, and their bloated and callused fingers to the constant cutting, cooking, and washing that they do daily.
But they have no regrets, as the sisters see themselves as preservers of their mother's legacy.
"How can I give up something that Mama passed down to me?" said Ms Jill Choong. "The skills are invaluable and unforgettable."
Her sister added: "We want to make Mama proud."
Madam Lai is thankful for her daughters' and customers' support. "To have success as a hawker is my proudest achievement."