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' bodies were found in their home on a semi-rural property outside 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 custody.
Director of Public Prosecutions solicitor Kathleen O'Keeffe said a crown expert was in the process of assessing Heggs.
"There's an issue about mental health that's been raised," Ms O'Keeffe told the court.
"After (the expert's) last appointment, she has requested some further documentation."
The case was adjourned for a fortnight, when prosecutors will have a better idea of how long it could take to finalise a psychiatric report, Ms O'Keeffe said.
The court has previously been told Heggs would attempt to rely on a mental health defence.
Heggs' solicitor Christopher Ford in February said a forensic psychiatrist had assessed her for the defence.
Judge Rami Attia adjourned the case until August 6 for a brief mention, which Heggs will not have to attend.
It's been more than 14 months since the boys were killed, rattling their small community.
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.Â
She was taken to a mental health unit at Orange Hospital before being transferred to Silverwater prison in Sydney.
Charge sheets before the court alleged she might have killed the boys as early as 10.30am that day.
Police have previously said there were no weapons involved in the alleged murders.
The boys' deaths shocked the town of 3500, where they were settling into 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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