Heather Wilkinson, 66, was one of four people who ate beef Wellington at Erin Patterson's Leongatha home in Victoria's southeast on July 29.
She died after the lunch, as did her sister Gail Patterson and brother-in-law Don Patterson, both 70.
The couple was honoured in a public memorial service last month, where their son Simon described them as being devout in their faith.
Simon Patterson was among the more than 300 mourners at the memorial service for Mrs Wilkinson at the Korumburra Indoor Recreation Centre on Wednesday.
Her husband Ian, 68, was also there after spending close to two months in the Austin Hospital after becoming critically unwell following the Leongatha lunch.
The Baptist church pastor returned home last month, in what his family described as a "moment of immense relief".
Heather and Ian's son David Wilkinson spoke at the service, describing his mother as a patient and kind person who loved to laugh.
"She loved being a mum and she loved us well," he said.
"She was uncompromising but full of grace."
Mrs Wilkinson had four children and six grandchildren, who also described her as kind, generous and loving.
"She had a beautiful smile and a contagious cheeky laugh," one of the granddaughters said in a recorded message played to the service.
"It's truly hard to come across someone as sweet and wonderful as her."
Police believe the symptoms the four diners experienced were consistent with being poisoned by death cap mushrooms.
Erin Patterson is considered a suspect as she cooked the lunch that is believed to have led to the deaths.
She was interviewed by police and released without charge but has since faced intense media scrutiny.
In a statement to police, Ms Patterson said she made a beef Wellington using button mushrooms from a major supermarket and dried mushrooms bought at an Asian grocery store.
The 46-year-old said she ate a serving and later suffered bad stomach pains and diarrhoea, contrary to the suggestion of detectives that she did not fall ill.
Victoria Police have not commented on Ms Patterson's statement other than to say it was not one taken by officers, nor have they provided any updates on their investigation.
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