Emotional family members have recalled "the darkest day of our lives" during a court hearing to sentence a teenage driver who killed two women and a teenage girl, and caused lasting injuries to another.

Michale Chandler, 29, Kelsie Davies, 17, and Sheree Robertson, 52, died at Maryborough on April 30 last year when the vehicles they were travelling in collided with a Mercedes-Benz driven by the then-13-year-old boy.

Crown prosecutor Chris Cook has told the Childrens Court of Queensland that earlier that day the boy, who cannot be named, was driven by friends to Maryborough, three hours north of Brisbane.

The court heard the boy had said the group was looking around the town for things to steal, in a practise he described as "creeping", when he found the 2003 car.

After stealing the car he drove it erratically at around 120kph through residential streets with his friends in the car describing him as "driving like an idiot", the court heard.

A forensic psychologist who did a risk assessment of the boy, Dr Luke Hatzipetrou, told the court the teen became angry when some of his friends criticised his driving ability.

The boy told authorities he reached speeds of 200kph while angry, with Mr Cook saying witnesses described the car moving "in a manic way" while swerving and crossing double white lines in the moments before the crash on Saltwater Creek Road.

Mr Cook told the court the Mercedes-Benz collided with the rear of the Holden Astra with Ms Chandler, Ms Davies, and Kayla Behrens, 17, inside.

The woman and two teens, all members of Maryborough's Reach Church, were "simply driving home" from the cinema, the court heard.

The Holden Astra collided with a Mazda 2 driven by nurse Sheree Robertson, 52, who was returning home after working a shift at Maryborough hospital.

All three died at the scene, while Ms Behrens was hospitalised for 16 days with severe injuries.

'Her loss has left a void'

Ms Robertson's mother, Jeanette Allen, wept in the public gallery as the evidence was heard, while the boy hung his head in the dock as the victim impact statements were read.

Ms Robertson's sister Liesa Latimer said her family's "lives were shattered" by the crash.

Ms Davies' mother, Susan Marquis, told the court her "heart was ripped from my chest" when police informed her of her daughter's death.

Ms Behrens said she had "deep emotional scars" and "survivor's guilt" following the loss of her friends, and lasting physical injuries which left her unable to run.

Early guilty plea

In July, the boy pleaded guilty to four charges, including one count of dangerous driving causing death and unlawfully using a car.

Defence barrister Ed Whitton said his client was remorseful for causing the deaths of the two women and teenage girl, and was "struggling to come to terms" with the consequences of the crash.

Dr Hatzipetrou told the court the boy had experienced domestic violence at the ages of 4 and 5, and fractured his skill through an accident at a skate park in 2021.

The boy had a cognitive impairment related to a lack of empathy, and Dr Hatzipetrou agreed with Mr Cook's proposition that his "moral compass was not properly formed".

Dr Hatzipetrou also agreed with Mr Whitton that staying in detention would have a detrimental effect on the boy's rehabilitation.

In prosecutor Chris Cook's submission he said the court should impose the maximum penalty of seven years, while Mr Whitton said the court should change the dangerous driving causing death charge to manslaughter.

In addition to the existing four charges, including one count of dangerous driving causing death and unlawfully using a car, the boy was charged with three new offences including unlawfully using a motor vehicle, stealing, and driving without a license.

The new charges relate to offences in the weeks leading up to the crash.

The hearing will continue in Maroochydore Children's Court on December 5.