Bufton, 68, faced Horsham Supreme Court on Wednesday for a plea hearing.

She was convicted in May of the murder of Colin Snooks across a 10-day trial.

A jury ruled that Bufton hit and killed Mr Snooks with a Holden Colorado utility vehicle on the driveway of her Fyans Creek property on October 30, 2017.

READ MORE: Fyans Creek homicide trial begins

During a plea hearing on Wednesday, the prosecution and defence presented evidence they believed should impact Justice Andrew Tinney's sentencing decision.

Crown Prosecutor Kevin Armstrong read a victim impact statement written by Mr Snooks' wife, Carol Snooks.

Mrs Snooks described an "emotional roller coaster" after learning of Mr Snooks' death.

"It took several days to accept that I would never see or hear from him again," her statement read.

"I'm angry at her. Colin and I had unresolved problems we needed to work through - she took away the chance (to resolve them)."

Mrs Snooks described feeling shock, guilt and anger. She described the difficulties of living in a small town in the aftermath of Mr Snooks' death.

"I would get strange looks when going into town," the statement read.

"I stopped going into town. My life has been all over the place for the last 20 months."

Defence lawyer Tom Danos told Justice Tinney that he should consider Bufton's declining health when determining her sentence.

Bufton was diagnosed with cancer in the months prior to Mr Snooks' death.

"Her prognosis is not exactly what one would describe as a glowing one," Mr Danos said.

"There is less than a 30 per cent survival chance past five years. Clearly it is a matter that has the potential to interact with her life expectancy. It's clearly a difficult issue."

Justice Tinney said the sentence "must be significant" due to the nature of the crime.

The maximum penalty for murder is life.

Mr Danos argued Justice Tinney should consider that the crime wasn't premeditated, and that Bufton had no priors.

He said Bufton was inside her home and ironing Mr Snooks' shirts on the day of his death - which he said was a sign that she still cared for him and did not plan to kill him.

However, Justice Tinney said this was irreconcilable with the evidence heard during the trial.

"Evidence accepted by the jury would indicate ... she reached such a level of anger at the refusal of Mr Snooks that he abide by her wishes and stay, that she killed him," he said.

READ MORE: Fyans Creek murder: How the trial played out

Mr Snooks was leaving Bufton's property on foot after she requested he stay and talk over a coffee. She got into his vehicle and ran him down.

"It's hard to reconcile that with the person she had been," Justice Tinney said.

"(Mr Snooks) was perfectly entitled to not to talk to her, if he didn't want to."

Justice Tinney said the seriousness of the offence was further compounded by Bufton's use of a vehicle.

In Mr Armstrong's submission, he referred to controlling behaviours which indicated a history of family violence.

"At first she sought to control Mr Snooks," he said.

The day of Mr Snooks' death, he had arrived at Bufton's property in the company of friend and sole eye-witness Benjamin Weston.

"Then she drove the ute around the house ... went inside, then saw Mr Snooks and Mr Weston starting to leave.

"She went back and proceeded up the driveway in an accelerating way. It must have been a period of some three or four minutes - I don't put that in the category of planned or premeditated ... but it was not completely spontaneous.

"She knew he had a slow gait and it made no sense for her to get in the car as she did.

"The essence of the offence is consistent with an early attempt at controlling, or controlling behaviour. She was enraged because she was unable to bend him to her will."

Justice Tinney said he had no evidence that Bufton "acknowledged or reflected on her wrong doing."

"In the material before me I can't see any indication of remorse," he said.

The court is expected to confirm a date for a sentence hearing in coming weeks.

Bufton remains in custody.

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