But the woman has told an inquest into the toddler's death that she didn't necessarily have concerns about the man's relationship with the family.
The child's death is one of four being investigated by Victorian State Coroner John Cain in a cluster inquest which began in Melbourne on Monday.
It's set to investigate the deaths of a baby and toddler over the next two weeks, before continuing in August with the investigation into the deaths of two other children.
Each child's family was involved with child protection and other family support services at the time of their death.
Suppression orders prevent any of the children, their families or workers connected with their cases from being identified.
The inquest will examine the extent of child protection's involvement with the families and whether the actions taken were sufficient and whether the lessons learned since the deaths of the children have gone far enough to reduce risks for children in future.
The first witness is a senior case worker who was involved with the family of a toddler killed in Victoria in the last decade.
Nobody has been convicted over the child's death.
The worker said she had met with the child's mother and her partner before the child died, and noted that the man was "protective" of the toddler's mum.
She later received an email notifying her that the man was a domestic violence perpetrator.
"Ahhhh, couldn't half tell!" she wrote in reply in an email revealed at the inquest.
The woman told the inquest she hadn't had concerns about the dynamic between the man and the child's mother, but conceded her reply might have implied otherwise.
She also agreed the response was inappropriate.
"Absolutely inappropriate and unprofessional," she said.
She was aware he had inappropriate discipline techniques for the toddler and other children, including requiring them to stand with their arms outstretched as long as they could as a punishment for wrongdoing.
But the woman said there were no parenting programs available for the man.
Her evidence is continuing.
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