Indonesian embassy officials met Siti Aisyah, 25, on Saturday in the Malaysian capital.
She said she was given the cash to smear Kim Jong-nam’s face with “baby oil” as part of a reality show joke.
Tests show Mr Kim was killed with the highly toxic nerve agent VX.
It is classified as a weapon of mass destruction by the United Nations.
Mr Kim died last week after two women accosted him briefly in a check-in hall at Kuala Lumpur international airport.
The airport has been swept for toxic chemicals by a forensic team, the fire department and the Atomic Energy Licensing Board.
There is widespread suspicion that North Korea was behind the attack, which it strongly denies.
A Vietnamese woman and a North Korean man have also been arrested in connection with the killing.
The Vietnamese foreign ministry confirmed that the Vietnamese national being held was Doan Thi Huong, born in 1988, saying she had told officials she thought she was taking part in a television prank.
At least seven other suspects are wanted by police.
After a 30-minute meeting with Siti Aisyah on Saturday, Indonesian Deputy Ambassador Andreano Erwin said: “She only said in general that somebody asked her to do this activity. She only said in general she met with some people who looked Japanese or Korean.
“According to her, that person gave her 400 ringgits to do this activity… She only said she was given a kind of oil, like baby oil.”
The officials said they did not see any physical signs that the suspect had been affected by the chemical.
Malaysia’s police chief Khalid Abu Bakar said on Friday that the presence of the nerve agent had been detected in swabs taken from Mr Kim’s eyes and face.
Mr Kim had sought medical help at the airport, saying someone had splashed or sprayed him with liquid. He then had a seizure and died on the way to hospital.
What is the deadly VX nerve agent?
- The most potent of the known chemical warfare agents, it is a clear, amber-coloured, oily liquid which is tasteless and odourless
- Works by penetrating the skin and disrupting the transmission of nerve impulses – a drop on the skin can kill in minutes. Lower doses can cause eye pain, blurred vision, drowsiness and vomiting
- It can be disseminated in a spray or vapour when used as a chemical weapon, or used to contaminate water, food, and agricultural products
- VX can be absorbed into the body by inhalation, ingestion, skin contact, or eye contact
- Clothing can carry VX for about 30 minutes after contact with the vapour, which can expose other people
- Banned by the 1993 Chemical Weapons Convention
Who was Kim Jong-nam?
The well-travelled and multilingual oldest son of late North Korean leader Kim Jong-il, he was once considered a potential future leader. He has lived abroad for years and was bypassed in favour of his half-brother, Kim Jong-un.
He had been travelling on a passport under the name Kim Chol. North Korea has yet to confirm that the deceased was actually Kim Jong-nam.
For many years, it was believed Kim Jong-nam was being groomed to succeed his father as the next leader.
But that appears to have come to an end in 2001 when Kim was caught sneaking into Japan on a fake passport.
He later became one of the regime’s most high-profile critics, openly questioning the authoritarian policies and dynastic succession his grandfather Kim Il-sung began crafting in 1948.