Mandy Stevenson, 40, who had a reputation for "doctor shopping" in Colac to get drugs, was found guilty by a County Court jury of one count of culpable driving causing death and three counts of negligently causing serious injury on the Colac-Murroon Road at Murroon at 4.45pm on July 6, 2011.

Judge Frances Hogan told Stevenson today it was "a truly unenviable task for a judge to have to sentence a mother for causing the death of her son and seriously injuring another son and two other children".

"The most concerning thing is your inability to accept responsibility for what you have done," she said.

"I know that you are suffering from a major depressive disorder as a consequence of Joshua's [her 17-year-old son's] death.

"Perhaps this, in itself, plays a role in you not being able to accept that you are legally and morally responsible for his death, as well as the injuries to Mitchell [her now 12-year-old son] and [he two other children aged 14 and 15].

"You state ... that you do not believe that you should be in prison because you need to be with your son, Mitchell, as he has lost his brother and now he is without you.

"You say that you need to go home so that you can all undertake family counselling to help overcome your enormous loss.

"Unhappily, this letter spells out to me that you really have very little insight into the magnitude of your offending if you think it would be appropriate for a judge to simply send you home right here and now."

Judge Hogan accepted that Stevenson's mind was occupied with the loss of Joshua and the guilt and pain that she feels, as well as the grave concern she has for Mitchell.

"He is only 12 years old and is without motherly care," the judge said.

"He is reliant upon being looked after by his father who has a serious criminal history for violence, dishonesty and drug offences.

"The grief that you feel is, no doubt, worse than any sentence that a court could ever impose.

"You are a tragic figure."

Judge Hogan said it was apparent from the clinical notes of Corangamite Clinic at Colac that Stevenson had a lengthy history of “doctor shopping” for prescriptions for benzodiazepines.

The judge said a doctor at the clinic alerted the Health Department just six weeks before the crash that Stevenson was a drug dependant person, was doctor shopping and seeking drugs of dependence, specifically xanax and diazepam.

"My overwhelming impression is that you had developed a lifestyle where you enjoyed the euphoric or sedative effect of prescription medication," the judge told Stevenson.

"You repeatedly had been warned about the dangers of your addiction, but did nothing about it."

Stevenson, a former heroin addict who was found to have had methadone, oxycontin, seroquel and Xanax in her system at the time of the crash, was jailed for seven and a half years, with a non-parole period of four and a half years.

-THE AGE