Amid a child custody battle the woman poured petrol on her ex-partner and threw a Molotov cocktail, causing a blaze that claimed both their lives.
Child Safety Queensland and the court system "missed opportunities" to identify the risk the mother posed due to the gender of the parties involved, Â coroner Ainslie Kirkegaard said.
An inquest was held after the mother in her early 30s broke into her ex-partner's southeast Queensland home and poured petrol on him as he slept in the early hours of March 10, 2022.
The ex-partner, also aged in his early 30s, was completely engulfed in flames when the mother threw the Molotov cocktail at him.
The previous day the Family Court had found the mother's mental health problems presented a lethal risk to herself and her children, ordering her kids be transferred to the custody of the father - her ex-partner.
An independent psychiatrist's report handed to the court found the mother presented a worst case scenario risk of suicide, kidnapping or killing her children - but not of harming her ex-partner.
Female perpetration of intimate partner homicide was extremely rare, Ms Kirkegaard said while handing out her inquest findings on Tuesday.
"Nonetheless, the circumstances in which the father and mother died provide valuable learnings about early and correct perpetrator-victim identification and to support effective risk assessment."
Ms Kirkegaard referred to input from violence prevention academic Dr Samara McPhedran throughout her findings.
"In Dr McPhedran's opinion, the way risks were assessed and identified by multiple agencies involved with the family was very strongly influenced by the gender of the alleged victim and perpetrator, and a limited understanding of male victimisation," Ms Kirkegaard said.
The mother had previously made baseless allegations that the father was sexually abusing one of their children and continued to make claims of increasing intensity and exaggeration despite no medical evidence, the inquest heard.
"Dr McPhedran's examination identified (the mother) as the perpetrator of a not uncommon form of coercive control against (the ex-partner), Ms Kirkegaard said.
"While multiple agencies recognised (the mother's) pattern of mounting unsubstantiated allegations against (the ex-partner) it was not identified as a form of domestic and family violence against him."
The ex-partner died in hospital on the same day of the fire.
The mother died from smoke inhalation after making no effort to save herself from the house fire, Ms Kirkegaard said.
Ms Kirkegaard found the former couple's children survived the fire due to the "incredibly brave" actions of their father's partner, who led them from the burning house to safety.
The Commonwealth should change Family Court confidentiality to provide information for reviews of domestic violence deaths, Ms Kirkegaard recommended.
Ms Kirkegaard said Child Safety Queensland had made significant investment and improvement in its handling of domestic and family violence.
The mother, ex-partner and their children cannot be identified for legal reasons.
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