William Tyrrell's foster mother is facing a fresh criminal charge as her case over an alleged assault of a child continues through the courts.
Both William's foster parents, who cannot be identified, appeared before a Sydney local court this morning on assault charges to which they have pleaded not guilty.
The foster mother, 56, and foster father, 54, were charged in November 2021 in relation to the alleged assault of a child at a home on Sydney's north shore.
The child is not William Tyrrell.
The pair used pseudonyms when they dialled in to today's court hearing virtually, and did not show their faces.
The specific allegations against them are suppressed.
Last Friday, NSW Police homicide squad detectives laid a fresh charge of common assault against the foster mother.
The new charge came after further investigations by detectives from Strike Force Rosann, which was established to probe William's disappearance.
The foster mother's lawyer, Sharon Ramsden, indicated to the court her client would plead not guilty to the new charge.
She also said her client would be seek to have the matter heard under the Mental Health Act.
Under section 14 of the act, a magistrate can dismiss charges and discharge defendants based on their mental state.
Ms Ramsden told the court a psychologist had assessed her client in relation to the initial assault charge but that she would now need to be evaluated again, given the new charge.
The foster father's lawyer, Lauren MacDougall, said her client would not seek to have the matter heard under the Mental Health Act, and was ready to proceed to a hearing.
The matter will return to Hornsby Local Court on April 29, when the foster mother's application to hear her proceedings under the Mental Health Act will be assessed.
