She is believed to have smoked cannabis before driving.
A coroner found Konrad was insufficiently restrained when his mother lost control of the vehicle on a sweeping bend while travelling up to 140km/h. He was flung 30m from the vehicle.
A dog had been sitting on a diagonal seatbelt that should have been available for Konrad, the coroner said.
Two other children in the car were wearing seatbelts, but Konrad was wearing only a lap belt when the car left the road, flipping and rolling several times.
Scott Truger told the court at Connon's sentencing the loss of his son was "heart wrenching and would never stop hurting''.
Connon was sentenced in the High Court to six months' community detention, two years' intensive supervision including drug counselling and psychiatric assessment, 200 hours' community work in road safety and child welfare programmes, and was disqualified from driving for two years.
Police are still investigating the crash that killed Truger on Friday.