Prosecutor Senior Constable Kerrie Moroney told the court each participant consumed the mushroom tea consensually and with full knowledge of the effects.

During the ceremony, the court was told, mushrooms were weighed and distributed as a tea in brown bowls with spoons – each participant chose the amount to consume up to a limit of 6g.

Dixon died while two others involved in the event were hospitalised.

An autopsy was unable to determine Dixon’s cause of death and no charges have been laid relating to her death.

The court was told prosecutors were unaware Mathews intended to plead guilty until Tuesday and had not contacted Dixon’s family to see if they wished to provide a statement.

Moroney said they were “extremely aggrieved by what happened”.

Mathews’ lawyer, Jon Ross, told the court the incident would continue to affect his client for the rest of her life.

“There’s no other way to describe this than a tragedy,” he said.

“It is important to note there is no evidence of a causal link between the event Ms Mathews hosted and the untimely passing of Ms Dixon.

“It was Ms Mathews who was with Ms Dixon, it was Ms Mathews who called triple-0 and it was Ms Mathews who provided CPR.”

He said his client had been practising alternative therapies such as reiki, sound healing, meditation and breath work for decades after seeing benefits in dealing with her own childhood trauma.

He said Mathews knew she “erred very badly” but highlighted that mushroom tea ceremonies were only a small and recent addition to her practice.

After Dixon’s death she stopped offering the ceremony to participants.

While he accepted she received a financial benefit from the event, he said it had not made her “fabulously wealthy”.

Ross took the court to a series of references from clients, including those present at the event, who described Mathews in glowing terms – as a trusted, highly skilled and compassionate person working with trauma survivors.

“We’re dealing with someone who through the course of her practice has helped many people,” he said.

One reference written by Marguerite Wilkinson described how Mathews was “calm and controlled” while dealing with Dixon’s health deteriorating.

“In the following weeks, Deanne was more concerned with us as a group and how we were all coping,” she said.

“My admiration for the way Deanne has handled herself throughout the last year is immense.”

Mathews’ partner, Benjamin Venes, wrote to the court that the mother of two held herself to a “high standard of integrity and responsibility” and had volunteered her time with Lifeline and supporting cancer patients at the Royal Melbourne Hospital.

Ross claimed media reports of Dixon’s death had an “intrusive extensive and prolonged” impact on his client.

Noting this was Mathews’ first contact with the law, co-operation with police and early plea of guilty, magistrate Julia Barling said she would not record a conviction.

But she disagreed with Ross’ submission that an adjourned undertaking to be of good behaviour was appropriate, instead fining her $3000.

“Regardless of any views you may hold about the benefits of taking specific substances … that is illegal and will not be tolerated by the community and will not be tolerated by the courts,” she said.

Mathews declined to comment as she left court into a waiting car.