Emma Louise L'Aiguille, 34, was charged in a Kuala Lumpur court this week with trafficking methamphetamines after she was arrested allegedly in possession of one kilogram (2.2 pounds) of the drug two weeks ago.
L'Aiguille, a nurse from Melbourne, made a tearful court appearance on Tuesday and her mother, Amanda Innes, said she had conveyed a "Mum, I'm sorry, I didn't do it" message back to Australia through consular officials.
"I felt shocked and numb when I was told," Innes told News Limited newspapers of learning that her daughter faced death by hanging if convicted.
"I don't want her to be (hanged), and the thought of that just terrifies me."
Innes appealed directly to the Australian and Malaysian governments to intervene.
"Please don't hang her," she said. "I just want her to be brought home alive."
Innes said her daughter was a "strong girl, but she was also very fragile".
"I'm not sure how she'll cope. I still don't think it's hit me, I can't get my head around it," she added.
L'Aiguille is alleged to have been driving the car the drugs were found in, and her lawyers said there had been three male passengers from Nigeria inside, including her boyfriend, referred to by Australian media as "Mac".
One of the trio, Anthony Esikalam Ndidi has been arrested and charged, but the other two are yet to be found.
Innes said her daughter -- a mother of six -- had been in a relationship with Mac for two years, and she feared something was wrong when L'Aiguille did not respond to telephone calls two weeks ago.
Drug trafficking carries a mandatory death sentence by hanging in Malaysia, where hundreds of people are on death row, mostly for drug offences, including Australian Dominic Bird, who was arrested in March.
Since 1960, more than 440 people have been executed in Malaysia, including two Australians put to death in 1986 for heroin trafficking -- the first Westerners to be executed under tough new anti-drug laws.
A spokesman for Foreign Minister Bob Carr stressed that it was "too early to speculate" on the outcome of the case, with hearings yet to begin and a verdict a long way off.
"Australia opposes the death penalty and our views are well known to Malaysian authorities," he said.