Christine Lyons has been found guilty of murdering Bendigo mother-of-four Samantha Kelly as part of a plan to take custody of her children.

Her co-accused and cousin-in-law, Ron Lyons, was found not guilty of murder, but guilty of attempted murder.

Christine Lyons' former lover, Peter Arthur, carried out the murder, striking Ms Kelly, 39, multiple times in the head with a hammer. He was jailed last year.

Ron Lyons was today found guilty of assisting Arthur with the murder, and Christine Lyons was also found guilty of attempted murder.

Christine Lyons, Ron Lyons and Peter Arthur lived at the same Kangaroo Flat property as Ms Kelly.

Christine Lyons is led from the Supreme Court after being found guilty of Samantha Kelly's murder. ( AAP: James Ross )

Christine Lyons was crying as she was led from the court today.

Reacting to the verdict outside the court, Ms Kelly's aunt, Tracey Lubcke, said she felt "the utmost relief" and that the jury had delivered justice for her niece.

"Thank God," she said.

"She was a good mum … and she was on her own and you had these brutal people, they swamped her. The evilness … these people aren't nice people."

Referring to Christine Lyons' reaction to the verdict, Ms Lubcke said:

"When you've seen these evil people and what they've done and how they did it, and the horrible things that I've heard and seen, I'm sorry but tears don't work on me from her."

'A loving, doting mother'

Ms Kelly's brother, Michael Kelly, praised the jury.

Ms Kelly was killed with a hammer. ( Supplied: Victoria Police )

"The jury got it right, they [have] done their job very well," he said outside court.

He said his sister was a "loving, doting mother", and he was glad the jury had not accepted claims she had abandoned her children.

"Her mother left her at a younger age and abandoned her — she never wanted to do that to her children," Mr Kelly said.

"We're always reminding them how mum loved them, how she'd always give them kisses and cuddles, how they'd always go to the park and have fun at the park together."

Mr Kelly said his sister's nine-year-old daughter had struggled to make sense of what had happened to her mother.

Mr Kelly's partner, Danielle Stevenson, said the jury had "put away three people that manipulated and used a very vulnerable person".

"We're so happy. [The verdict] was exactly what we wanted.

"We couldn't have asked for a better outcome … the jury [has] done an amazing job. It would have been so hard for them to take in all the information."

Samantha Kelly's aunt, Tracey Lubcke, said she felt relieved at the jury's decision. ( ABC News )

A plea hearing will be held in August before Justice Stephen Kaye hands down sentences.

The prosecution had argued Christine Lyons was desperate to have a family of her own.

Ms Kelly was killed in January 2016 and her body was found in bushland south-west of Bendigo the following month.

The jury of seven women and five men took six days to reach its verdict.

Arthur was last year sentenced to 16 years' jail after pleading guilty to bashing Ms Kelly to death in the bungalow she lived in at the rear of the Kangaroo Flat property.

In February, Arthur had a further five years added to his sentence after prosecutors successfully appealed his original sentence.

Peter Arthur (L), Ron Lyons and Christine Lyons outside the Kangaroo Flat home they shared. ( Supplied: The Age )

A plot to kill and lie

The trial for Christine Lyons and Ron Lyons was told the trio had plotted over several weeks to kill Ms Kelly, motivated by Christine Lyons' "very powerful desire to have a family".

"Christine desperately wanted children," Prosecutor Fran Dalziel told the jury.

"When Peter Arthur killed Samantha Kelly, he did so so that Christine Lyons would take up parenting of Samantha Kelly's children."

The trial was told Christine Lyons had approached 10 people to have a baby for her but none of them had agreed.

The jury was told that at the time of Ms Kelly's death, her four children had been moved into the main house, away from their mother's bungalow.

Samantha Kelly was last seen using an ATM in January 2016. ( Supplied: Victoria Police )

Ms Dalziel said Christine Lyons had changed the children's names.

The trial was told Christine Lyons had spoken a number of times, including to Ron Lyons and Arthur, about drugging Ms Kelly and wanting her to take a "permanent holiday".

After Ms Kelly's death, the trio agreed to tell people Ms Kelly had left her children after telling them she had had enough, the court was told.

They also agreed to say she had developed a drug problem, the jury heard.