The family of a newborn baby and young couple who died after Jenny Hayes burned down their home say justice has not been served, as she was jailed for at least eight years.
Hayes, 48, faced the Supreme Court on Friday by video link from prison, where she learned her fate after pleading guilty to three counts of arson causing death over the December 2020 fire.
Abbey Forrest, 19, Inderpal Sohal, 28, and their 19-day-old daughter Ivy died from carbon monoxide poisoning in the blaze, which Hayes lit in retribution after a man had wronged her.
Justice Elizabeth Hollingworth handed Hayes a 13-year prison sentence with an eight-year non-parole period.
With time already served she could be eligible for release in almost six years.
Ms Forrest's mother Elizabeth said she was "absolutely devastated" about the length of Hayes' sentence.
"We feel that no justice has really been done according to what has happened," she said, outside court.
"When she [Justice Hollingworth] started taking time off for things, it felt like it just ripped us apart.
"I know nothing will bring them back, but I just can't believe the sentence we've got now."
Alan Forrest said the family and their supporters felt they had been let down.
"We don't get closure by this, we get three life sentences," he said.
Hayes was furious about a sexual encounter ending badly when she set fire to the family's newly rented Point Cook townhouse, just before 2am on December 2 of that year.
Mr Sohal had allowed a friend to use their downstairs bedroom.
The friend had hired Hayes, a sex worker, and she provided services but there was a dispute and he left.
Hayes said the man raped her and then stole cash from her handbag.
She sent him a series of angry texts, threatening to charge him with rape and send him to jail.
"I'm setting your house on fire right now," she texted.
After waiting in her car for the man to come back, Hayes stormed back into the downstairs bedroom and used a lighter to set fire to a mattress.
The young family, who were asleep upstairs, had no chance to escape as their home became engulfed by flames.
Hayes took photos of the blaze and sent them to the man, taking more pictures as she drove away.
Justice Hollingworth was critical of Hayes' decision to take photos instead of calling emergency services.
"Three innocent people lost their lives as a result of your actions. The fire spread so quickly that Mr Sohal and Ms Forrest were unable to escape it, despite their best efforts," she said in court.
"Ivy was the most vulnerable of all, being totally incapable of helping herself."
She accepted that Hayes did not know anyone was home when she lit the deadly fire, as she was in hysterics when told by police about the three deaths.
"Through your hysterical crying, you kept expressing disbelief that the fire had burned the townhouse down, or that anyone had been hurt," she said.
"You remained distraught throughout your formal record of interview, repeatedly stating that you didn't know that people were in the house."
She took into account Hayes' genuine remorse, early guilty plea and found her mental health conditions and the COVID-19 pandemic would have made her time in custody more difficult.
Hayes, who has already served almost two years of her prison term, is the fifth person in Victoria to be sentenced for arson causing death.