Mushroom cook Erin Patterson felt her estranged husband had been “isolating her” from his family before she served up a poisonous lunch that killed her former in-laws, a jury has been told.

Patterson, 50, has been charged with three counts of murder and one of attempted murder over the July 29, 2023 meal but she has pleaded not guilty and claims the meal was a terrible accident.

The only survivor from the lunch was Heather’s husband Ian.

A child protection worker gave evidence on Thursday to Patterson’s trial, in regional Victoria, where she detailed her visit with the mother-of-two while she was in hospital two days after the lunch.

Katrina Cripps said she spoke to Patterson, her two children and Simon at Monash Hospital.

Cripps said to the jury Patterson told her that her relationship with Simon had changed in September 2022, after she asked to receive child support from him and that he became “nasty towards her”.

“She said that Don and Gail had been like the parents she hadn’t had, her parents had died quite some time ago,” she told the jury.

“She cared and loved them very much and felt very supported by them but that relationship had also changed recently as well.

“She felt isolated from them.”

Asked by prosecutor Sarah Lenthall what she meant by isolated, Cripps said “she felt that he was isolating her from (his) family”.

“Family events he would go to normally, she wasn’t going to or wasn’t invited to,” Cripps said.

She said Patterson told her Simon had been controlling, made her doubt herself as a mother and “also impacted her self-esteem”.

Cripps said Patterson told her she’d received an inheritance from her grandmother and she had given half to Simon when they separated in 2015.

“She had done that because that’s what she thought you did when you separated,” Cripps told the jury.

Patterson told her she’d made a beef Wellington with green beans, mashed potato and packet gravy for Don, Gail, Heather and Ian, on July 29, and served leftovers to her kids the next day.

She told Cripps she had eaten “half” of the lunch and had scraped mushrooms off the dish when she served it to her kids.

“She said that she had started to feel unwell after that … and was experiencing loose bowel movements,” Cripps said.

“She said that Simon had told her that the others were really sick too.”

Cripps said she visited Patterson the next day, on August 2, after she had been discharged from Monash Hospital.

She toured her Leongatha home and helped Patterson contact a public health official who was trying to speak to her about the origins of the mushrooms in the meal.

Patterson could not recall the Asian store she bought some of the mushrooms from, said they were “strong smelling” and she had rehydrated them and mixed them with fresh mushrooms from Woolworths, Cripps said as she overheard the call.

“Did you ask Erin Patterson if she had picked the mushrooms used in the lunch?” Lenthall asked.

“Did she answer you?” Lenthall continued.

“No … she was looking at her phone,” Cripps said.