Two months into the maid's stay, the cracks began to appear.
Her four-year-old daughter would avoid their maid when she and her husband were at home, and ask them to take care of her instead.
One day, her daughter came up to her, and knocked her head on the wall.
Said the child: "Aunty hit my head."
But she merely warned the Myanmar maid, Su Su Hlaing, 31, saying it should be the last time.
(We are not naming the parents or their daughter as the girl is a minor.)
At the time, the maid also started giving monosyllabic replies whenever she or her husband called home. Still, they thought little of the signs.
Her work was adequate. In front of the couple, the maid would be caring towards the child, and even play with her.
But two months later, the daughter began to cry whenever her mother was about to leave for work in the morning.
"She would say, 'mummy take me.' My husband and I thought it was just that she wanted me, which was normal. But I was a little confused," the girl's mother told The New Paper on Tuesday evening.
So the couple bought a CCTV camera and installed it in their flat's living room.
What the spy camera caught over eight hours from Feb 9 to 10 shocked them.
The maid was seen slapping the girl on the head.
She was also caught hitting her on her right arm and pulling her hair.
And, frustrated with trying to get the girl to eat, Hlaing went to the kitchen and took a knife with a 20-cm long blade, which she pointed at the child while advancing towards her.
The child shrank away, frightened.
Then, when Hlaing sat opposite the girl, she flung the same knife, which landed next to the girl.
Incensed, the parents reported the maid to the police on Feb 11.
Said the girl's mother: "If we caught all that over two days, what more could have happened over the last five months?"
On Tuesday, Hlaingwas sentenced to three months' jail for criminal intimidation, with an intent to cause the girl alarm.
After watching the video, the mother said, she did not want Hlaing in their home.