Erin Patterson has been charged with trying to kill her ex-husband at least three times in the years before she allegedly fed his family a lunch of deadly mushrooms.
The new details were revealed in court documents, as the 49-year-old woman faced court on Friday and five of attempted murder.
She is accused of killing her former in-laws, Don and Gail Patterson, both 70, and Gail's sister Heather Wilkinson, 66.
All three died in hospital days after consuming a meal at Patterson's Leongatha home, in South Gippsland, on 29 July this year.

Heather Wilkinson (left) and Don and Gail Patterson (right) died in hospital after eating a meal suspected to have contained poisonous mushrooms. Credit: Supplied
Police allege Patterson first attempted to murder Simon between 16 and 17 November 2021.
She is then accused of her ex-husband's attempted murder in 2022, between 25 and 27 May, and on 6 September.
It's further alleged she attempted to kill Simon at the 29 July lunch.
The fifth attempted murder charge relates to Wilkinson's husband Ian, 68, who spent close to two months in hospital critically ill after the lunch and is still in recovery.
Media filled three rows of seating as Patterson appeared in Latrobe Valley Magistrates Court on Friday morning, wearing a beige jumper and reading glasses, for a brief hearing.
Flanked by two custody officers in safety glasses, Patterson showed no emotion as she sat in the dock on the side of the court room.

The woman accused of murdering three people by allegedly serving them death cap mushrooms at her home has faced court in Victoria. Source: AAP / James Ross
"There needs to be analysis of computer equipment seized yesterday," he told the court.
Magistrate Tim Walsh appeared annoyed and questioned why it would take "20 weeks to analyse computer equipment in a triple murder, where the informant is confident he had enough evidence to charge this lady yesterday?"
Defence lawyer Bill Doogue, who said he had been engaged with Patterson "for a while", agreed to the delay.
"It seems to be based on a lot of analysis that we haven't received and hasn't even been completed, which is why they're asking for extra time," he said.
Walsh explained to Patterson that the matters they were discussing were administrative.
"So don't be too concerned alright, the important thing is this matter progresses through the system as fast as possible," he told her.
"OK," she replied, nodding her head.

A sketch of Erin Patterson at the Latrobe Valley Magistrates Court on Friday. Source: AAP, Supplied by Danyal Syed / Anita Lester
"I imagine the materials are going to be voluminous, and that it does go to Melbourne so that a particular magistrate can manage the matter," Walsh said.
Doogue said Patterson did not have any custody management issues.
The magistrate told Patterson there was no application for bail as he did not have the power to grant it.
If she applies for bail, that will need to be heard in the Supreme Court at a later date.
The accused triple murderer was silent as she was escorted out of the court room.
Patterson was remanded in custody and will next face court via video link from prison on 3 May next year.