Kathleen Joyce Heggs is facing two counts of domestic violence murder over the deaths of Max and Sam Johnson, aged seven and six.
The brothers were found dead in their home on a property in the outskirts of Coonabarabran, in northwest NSW, on the afternoon of May 5, 2025.
The 67-year-old's case was briefly mentioned in Dubbo Local Court on Thursday morning, but she did not appear via audio-video link from Silverwater jail.
Heggs' solicitor Christopher Ford said he was awaiting a professor of psychiatry to complete a report, which was due in coming days.
"I need that before we can have a case conference," Mr Ford told the court.
Magistrate Brett Shields adjourned the matter until March 5.
During a previous mention in 2025, Mr Ford said Heggs' defence would relate to her mental wellbeing.
"This is going to be a question of my client's mental health at the time of the offences," Mr Ford said.
Heggs was the sole carer for the boys and the family had moved from the NSW Central Coast to Coonabarabran about a year before the alleged murders.
Two junior police officers broke into their house after a message sent to the communities and justice department triggered an emergency response.
They found the boys' bodies in their bedrooms.
Heggs, their maternal grandmother, had harmed herself and was arrested. She was taken to a mental health unit at Orange hospital before being transferred to the Sydney prison.
Charge sheets before the court alleged she may have killed the boys as early as 10.30am on May 5.
Police have previously said there were no weapons involved in the alleged murders.
The boys' deaths shook Coonabarabran, a town of 3500, where they went to the local primary school and attended karate classes.
Community members held a candlelight vigil in a park by the Castlereagh River, where they planted two trees in the boys' honour and displayed the yellow karate belts they were due to receive.
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Kids Helpline 1800 55 1800 (for people aged 5 to 25)
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