William Tyrrell's foster mother allegedly used a wooden spoon to hit a young child in the head as part of a "pattern of ongoing violence", a Sydney court has heard.
The woman, who cannot be identified, fronted Parramatta Local Court today, flanked by her husband and a supporter.
The 56-year-old is facing two counts of common assault and two intimidation offences, relating to a child in her care.
The child is not William Tyrrell and the woman has pleaded not guilty.
More details about the charges, which relate to alleged incidents from last year, were today revealed in court.
It's alleged the woman hit a 10-year-old girl in the head with a wooden spoon, kicked her in the thigh and threatened to "break" her.
The court heard that, in July last year, the couple had a younger girl placed into their care, which led the older girl "feeling left out".
The police prosecutor said the offences involved "a series of attacks" and represented "a pattern of ongoing violence".
Magistrate Peter Feather said the family's dynamic changed when the younger girl was introduced.
"There are interchanges that occur between parents and children in a family setting ... this change caused differences in terms of dynamics in the family," he said.
"This is [a case] where a child has been misbehaving."
Magistrate Feather accepted the foster mother had multiple ongoing mental health issues.
"I'm satisfied that ... the accused suffers from major depressive disorders, and post-traumatic stress disorder," Magistrate Feather said.
However, he dismissed the woman's bid to have the matter dealt with under the Mental Health Act.
Earlier this year, William's foster father, who also cannot be named, pleaded not guilty to similar charges.
The 55-year-old man will front court in January next year.
William disappeared from his foster grandmother's home on the Mid-North Coast in 2014, aged three.
No one has ever been arrested or charged over his disappearance.
