Mental health will be the central issue in the case of a woman accused of murdering her two young grandsons in their rural home.

Kathleen Joyce Heggs, 66, has been charged with 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 the outskirts of Coonabarabran, in northwest NSW, on the afternoon of May 5.

Heggs, their maternal grandmother, had harmed herself and was arrested and taken to a mental health unit at Orange hospital.

Her case was briefly mentioned in Dubbo Local Court today, and she was not required to appear from custody.

“This is going to be a question of my client’s mental health at the time of the offences,” Heggs’ solicitor Christopher Ford told the court.

Ford did not object to an application by NSW Police to conduct a forensic procedure on Heggs.

Magistrate Brett Shields confirmed an order for the unspecified procedure to be carried out.

Before the matter was heard in front of the magistrate, Ford had an exchange with a Legal Aid lawyer who had been initially instructed by Heggs.

Ford, via video-link from Sydney, announced he was appearing for Heggs.

Senior Legal Aid solicitor Bill Dickens said he had spoken to Heggs earlier in the morning and received instructions from her.

Ford insisted he was representing her.

“I’ve just spoken to her and she’s trying to contact you,” Ford said.

Dickens repeatedly asked Ford not to discuss Heggs’ legal representation in an open forum.

“Please stop talking about this in an open court in the presence of the media,” Dickens said.

Ford later asked that legal documents be sent to his office in the city.

Heggs was the sole carer for her grandsons and the family had moved from the NSW Central Coast to Coonabarabran about a year ago.

Following a message that alerted the communities and justice department, two young police officers entered their home located on a semi-rural property, prompting an urgent reaction.

They found the boys’ bodies in their bedrooms.

After treatment in a mental health facility, Heggs has been taken into custody, a NSW Corrective Services spokeswoman confirmed.

At Heggs’ first court appearance, five days after her arrest, police documents 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, where they went to the local primary school and attended karate classes.

Residents gathered for a candlelight vigil at a park near the Castlereagh River, planting two trees to remember the boys. They also showcased the yellow karate belts the boys were set to earn.

Warrumbungle Shire Councillor Kodi Brady read a poem describing the boys as “wild as March hares, full of spark and flame”.

Heggs’ case will return to court on July 10.

1800 RESPECT (1800 737 732), Kids Helpline 1800 55 1800 (for people aged 5 to 25), Lifeline 13 11 14, beyondblue 1300 22 4636