It has been more than two years since Jessie O'Brien, 33, and her husband Peter James O'Brien, 52, were charged with manslaughter over the death of their 14-month-old daughter.

Yesterday, Jessie O'Brien pleaded not guilty to the charge.

Her estranged husband, on the same charge, was not in court after a successful application for separate trials was made during the last district court sittings in November.

A jury was empanelled yesterday and they heard Crown Prosecutor Wayne Creasey's opening statement.

Mr Creasey echoed Judge Garling's comments to the jury, saying it was important the jury remained impartial, referring specifically to photographs to be distributed as part of the Crown's case.

Judge Garling described the case as "fairly emotional" and "fairly difficult" due to the death of a young child, and he instructed the jury to "put emotions aside".

The Crown Prosecutor began by outlining the case to the jury and the incidents leading to the discovery of the child's body in a vehicle at the Raleigh deviation and the subsequent arrest of Mrs O'Brien in February 2000.

Mr Creasey said the O'Briens' vehicle was stopped by Coffs Harbour police following a statewide search based on concerns the child could become seriously ill without urgent medical attention.

Mrs O'Brien sat in the dock while members of the jury heard that Department of Community Services' Richard Lewandowski, had visited Jessie and Peter O'Brien at their Toorak Court home on January 28, 2000, after concerns were expressed about the well-being of their youngest daughter.

The first witness in the trial, Mr Lewandowski told the court how, after observing the child, he advised the O'Briens to take their daughter to the doctor.

Mr Lewandowski said DoCS received notification the child was "very ill, appeared to be losing weight and was yellowish".

Mr Creasey told the jury Mrs O'Brien had taken her daughter to see a doctor the next day, but had ignored the doctor's advice to take the child to Port Macquarie Base Hospital for tests.

Mrs O'Brien would not allow her daughter to undergo blood tests as it was against her religion, and wantedher to see a naturopath.

Mrs O'Brien's barrister, Mr Formosa, said his client had been concerned her daughter would be taken from her, and out of fear, agreed with the doctor to take her to hospital.

Mr Formosa said his client believed she was entitled to a second opinion and, opting for a natural treatment, she decided to take her to a naturopath.

On January 29, 2000, the O'Briens headed to Queensland to find alternative treatment for their daughter.

The court heard the child's health improved slightly while receiving natural treatment, but died in her mother's arms about midnight on February 8, 2000.

Police stopped and searched the vehicle on their return to Port Macquarie on February 9, when the child's body was found wrapped in a blanket.

The toddler's body was taken to Glebe for a post mortem, which proved malnutrition was the cause of death, Mr Creasey said.

The trialwill continue at Port Macquarie District Court today and is expected to finish later this week.