Peta Warland, 33, who went into jail to begin her sentence on Tuesday, will be eligible for parole in January, 2022, after serving just 16 months, a sentence Ms Crews' loving family later lamented was not long enough.

Ms Crews' family had packed into Newcastle District Court to hear Judge Tim Gartelmann's judgement, three days after they had read emotional victim impact statements, attempting to articulate the profound grief and loss they felt.

Ms Crews' daughter, Jade Buckley, had outlined the traumatic experience of being on the phone to her mother at the time of the crash, while Ms Crews' husband, Robert, had told of the struggle life had been without his beloved wife, saying she was "a beautiful soul and her memories will never fade from my thoughts".

Warland told police she had been woken up at 7am on May 13 last year by her boyfriend and had left home shortly after to drive him to work.

It was during the drive home to Belmont North from Gateshead - after travelling more than 11 kilometres - that Warland failed to follow the curve on the Pacific Highway and drove over the concrete median strip.

Her vehicle didn't brake as she crashed into Ms Crews' car coming the other way, the impact causing both cars to spin out of control.

With Ms Crews trapped in her car suffering critical injuries, witnesses, police and paramedics who interacted with Warland all thought she was affected by drugs.

Warland's version of when she last smoked cannabis, how much she smoked and how regularly a user she was varied in accounts she gave to police, a psychologist and in court on Tuesday.

A forensic pharmacologist opined Warland would have been significantly impaired by cannabis when she got behind the wheel and said if she was not a regular user then she would have last used the drug less than three hours before the crash. "The circumstances in which she drove in her impaired condition were such as to expose many other roads users to risk," Judge Gartelmann said.