Out of frustration, a maid punched a sickly elderly woman suffering from Parkinson's disease - a long-term degenerative disorder of the central nervous system.

Gracy Law Rice, 24, was hired to look after Madam Wong Poh Lin, 72, who is weak, unable to speak and struggles to walk.

The Myanmar national was jailed for four months yesterday after pleading guilty to assault.

Madam Wong's eldest daughter had employed Rice and the maid started working in the elderly woman's Whampoa Drive flat on April 8 last year.

Madam Wong lives in the unit with her husband. Their children, who live elsewhere, visit them once every two weeks.

Rice's duties included bathing Madam Wong, helping her to exercise and ensuring that she took her medication. It was her first time working in Singapore.

On July 10 last year, she was feeding Madam Wong some porridge when some food dribbled out of her mouth. Frustrated, Rice punched her chest twice with her right fist.

Madam Wong's daughter later discovered bruises on her mother and informed her brother, who alerted the police on July 12 last year.

At Tan Tock Seng Hospital later that day, several injuries were found - including bruises on her chest and left buttock, and cuts on her right shin, right elbow and left cheek.

Deputy Public Prosecutor Ruth Teng said: "According to the accused, she had caused the victim to sustain the injuries on her face, right leg and buttocks accidentally.

"She could not explain how the victim had sustained the other injuries which the doctors found upon examining the victim."

Rice said she hit Madam Wong for the first time in the July 10 incident, DPP Teng told the court. The maid said she only shouted at Madam Wong on previous occasions when the victim did not eat her food. DPP Teng urged District Judge Lim Keng Yeow to jail Rice for four months and stressed that Madam Wong was a vulnerable victim.

Rice's lawyer, Mr Foo Juyuan, who was assigned by the Criminal Legal Aid Scheme, asked the court to jail his client for three months.

He said: "This was a one-off incident with no other evidence suggesting that the other injuries...were intentionally caused by Gracy to Madam Wong."

For causing hurt, Rice could have been jailed up to two years and fined up to $5,000.