An inquest into the death of three-year-old Nia Glassie has been told her older brother was injured in similar circumstances 14 years earlier.
The Rotorua girl died of severe brain injuries in hospital after being abused and tortured by her mother's partner and his brother in August 2007.
Wiremu Curtis, 19, and his 22-year-old brother Michael were convicted of her murder.
The girl's mother, Lisa Kuka, was convicted of manslaughter for failing to protect her child, and gave evidence at the Rotorua Coroner's Court on Monday.
Nia Glassie's brother Roy was nine months old when he was admitted to hospital with non-accidental injuries of a swollen leg and bruising around the ankles.
He was being looked after at the time by Miss Kuka's then-boyfriend.
Acting chief social worker Kelly Anderson told the inquest there was a similarity between both cases where a child of Miss Kuka's suffered at the hands of her partner.
Ms Anderson said there was no other concerns expressed about the mother's parenting and the 14-year period between the cases.
Miss Kuka told the court she had no idea why her partner was not charged over her son's injuries and that she ended the relationship straight away.
Earlier, Miss Kuka said she did not turn a blind eye to the abusive treatment her daughter was receiving and had no idea of Wiremu and Michael Curtis's actions. She told the court she never saw her daughter being abused.
Miss Kuka said that, had she known, she would have taken immediate steps to end her relationship and move out of the house.
She described Nia as a "bright, bubbling", brown-eyed child, who did not deserve to be treated badly or to die.