The convicted killer is not expected to be in the courtroom when three Victorian Court of Appeal judges hand down their decision on Friday morning.
She will instead watch the ruling remotely from the Dame Phyllis Frost Centre, the prison in Melbourne's west where she is currently serving a life sentence.
The 52-year-old claims she suffered a substantial miscarriage of justice when a jury found her guilty of murdering her lunch guests.
Jurors believed she deliberately served beef Wellingtons laced with death cap mushrooms to her former in-laws Don and Gail Patterson, 70, and Gail's sister Heather Wilkinson, 66.
The three guests died after the July 2023 lunch at Patterson's Leongatha home, in regional Victoria, while Heather's husband Ian fell seriously ill from the meal but survived.
At appeal, Patterson's lawyers pushed for her convictions to be quashed, arguing she suffered a miscarriage of justice.
They pointed to the "catastrophic" decision to sequester jurors in the same hotel as the lead detective and the "unfair and oppressive" cross examination the killer faced.
Victoria's top prosecutor said those arguments were without substance as he pushed for Patterson to be handed a stronger sentence.
She was jailed for life with a non-parole period of 33 years but Brendan Kissane KC argued her cruel betrayal of her lunch guests renders any opportunity for parole manifestly inadequate.
If Patterson is successful in her appeal, the court could grant her a retrial or a complete acquittal of her murder and attempted murder convictions.
If she loses, the court could then dismiss the prosecution appeal and leave her sentence unchanged.
Alternatively, they could grant the prosecution's appeal and re-sentence Patterson to more time behind bars.
Justices Stephen McLeish, Lesley Taylor and Peter Kidd will hand down their decision at 10am on Friday.
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