Erin Patterson had shared with true crime fans her love of mushrooms, excitement over buying a food dehydrator and plans to cook beef Wellington.

The 50-year-old mother of two has pleaded not guilty to all counts against her, including three murder charges for killing her estranged husband’s family after feeding them lunch at her Leongatha home.

Don and Gail Patterson and Heather Wilkinson all died in hospital from death cap mushroom poisoning after eating a beef Wellington Patterson had prepared for them on July 2023.

Patterson claims it was “a terrible accident”, her lawyers said last week.

Three members of a true crime Facebook group Patterson was part of gave evidence on day five of her Supreme Court trial in Morwell, regional Victoria.

The group was created to go over the case of convicted baby killer Keli Lane, but also discussed other cases, politics and to share personal stories, the jury was told today.

She was well-regarded, she was a really good researcher,” group member Christine Hunt said about Patterson’s online reputation.

Another member, Daniela Barkley, said in 2023 Patterson had shared photos of a black dehydrator with mushrooms inside, which was shown to the jury.

“She was a bit excited that she’d purchased a food dehydrator,” Barkley said via video link.

Screenshots of Patterson’s messages to the group were also shown to the jury.

“I’ve been hiding powdered mushrooms in everything. Mixed into chocolate brownies yesterday, the kids had no idea,” she wrote in one post.

Jenny Hay, another online friend, said Patterson “seemed to really like mushrooms”.

In the weeks before the deadly mushroom meal, Patterson asked the group if anyone had cooked a beef Wellington and if they had advice, the jury was told.

“Towards the end of July, Erin said she was making beef Wellington,” Hay said.

“I think she was at the supermarket and she messaged us something about the beef that she was buying.”

She said Patterson had told them the mushrooms came from an Asian grocer.

Hay said Patterson asked her for tips on how to make sure the beef Wellington pastry did not go “soggy”, as it was one of Hay’s favourite dishes.

Barkley, who is a vegetarian, said she joked: “I’d make a tofu Wellington”.

“Everyone thought that was awful, so we had a good laugh about that,” she said.

Earlier, Patterson’s estranged husband Simon finished his evidence to the jury after almost three days in the witness box.

Defence barrister Colin Mandy SC put it to Simon that he had asked Erin – two days after the lunch – “is that what you used to poison them?”, referring to the food dehydrator.

“I did not say that to Erin,” Simon responded.

The jury of 15 people were shown messages from a family group Signal chat between Simon, his former wife and his parents – in December 2022 – after he last week claimed she had sent “extremely aggressive” messages to his mother and father.

But the alleged aggressive messages, which he said were from a few months later, have not yet been shown to the jury.

“It was very emotive, having a crack at me and accusing me of some things in response to what I’d messaged her about,” he said.

After his parents tried to help Erin and Simon resolve a dispute over his child support payments, his mother Gail took a step back and stopped reading messages from Erin in the group chat, Simon said.

“Mum really struggled with anxiety,” he said.

The trial before Justice Christopher Beale will continue tomorrow.