A Perth woman has told an inquest that she had every faith that "natural" therapy would cure her daughter's cancer, although she later died.

Her daughter, 10-year-old Tamar Stitt, was diagnosed with liver cancer in 2009.

The inquest has heard Tamar's parents refused chemotherapy for their daughter. She received "natural" therapies such as clay wraps and herbal teas in El Salvador, her mother's homeland.

She died three months after the cancer diagnosis.

Her mother, Arley Stitt, has told an inquest she had seen many people cured of their ailments through so-called natural therapies, but conceded that none of those people had cancer.

"I had so much faith it was going to work for Tamar," she said.

She added Tamar was "a very mature girl".

"If she didn't agree with our treatment, she would have been very clear with us," Ms Stitt said.

"I wouldn't have pushed her."

Ms Stitt said Tamar at first responded well to the treatment - she was brighter, had started to eat more and even wanted to go to school.

She said her daughter was initially given a 30 per cent chance of survival with chemotherapy, so she started natural remedies believing she had a 100 per cent chance of curing her.

When Tamar's health deteriorated, her mother decided to allow chemotherapy in El Salvador, but Tamar did not survive.

Ms Stitt cried when describing her relationship with her daughter, saying they were like sisters.

She said the months following Tamar's diagnosis were "a nightmare".

Tamar's father previously told the inquest he believed natural therapies, including clay he collected from Kenwick in south-eastern Perth, had treated his own chest infections, stomach ailments and a cut thumb.

Doctors who testified said they had tried to convince Tamar's parents to allow her to undergo chemotherapy and surgery.

The inquest continues.