Angie Liaw, 32, had been on trial in the Victorian County Court, charged with assisting her husband Chee Kit "Max" Chong, 47, intentionally possess a slave.
But Judge Michael Cahill on Thursday told the jury it was no longer required to decide Ms Liaw's case and she would instead be found not guilty of the charge.
"Having considered all of the evidence in the prosecution case, I've decided as a matter of law that Ms Liaw should be acquitted of the charge against her," the judge said.
Prosecutors alleged Chong kept the 61-year-old Malaysian woman, who cannot be legally identified, as a slave between January and October 2022.
It's alleged he controlled her access to the outside world, and made her clean and care for his children unpaid.
The woman was allegedly found with bruises and injuries to her leg and ears, which prosecutors claimed had been caused by assaults on her committed by Chong.
The woman escaped from the couple's Melbourne home in October 2022, the jury was told.
She died in 2024, however her recorded interview with police in 2022 was played to the jury.
Prosecutors had alleged Ms Liaw benefited from the woman's domestic services and asked Chong to give her instructions or tasks, helping Chong in controlling her.
But Judge Cahill found there was no case for Ms Liaw to answer and the jury should not be tasked with deciding her fate.
The judge said the jurors would still have to reach verdicts for Chong, who is charged with intentionally possessing a slave and three counts of assault.
"You must not draw any adverse inference against Mr Chong because of my decision Ms Liaw should be acquitted," the judge said.
Chong has denied the allegations, with his lawyers asking jurors to question why the victim may have exaggerated her claims.
Chong's lawyers and the prosecution are expected to begin their closing addresses later on Thursday before Judge Cahill provides his final directions to the jury.
The jurors will then be sent out to deliberate on their verdicts.