In short:

The children of Frances Crawford have given evidence at the trial of her husband, Robert Crawford, for murder.

Ms Crawford's son Jake Crawford, told the court none of the children wanted her to associate with their father for fear for her safety.

What's next?

The trial continues.

The son of a woman who was allegedly killed by her husband at a rural southern Queensland property has told a jury, none of her children "wanted her in an environment with my dad" and he was "scared for her safety".

Robert John Crawford is on trial in Brisbane, accused of murdering 49-year-old Frances Crawford in July 2024.

The former RAAF pilot, also aged 49, has pleaded not guilty.

Prosecutors allege he caused her death, before taking steps to make it look like she had a fatal ride-on mower accident at their Upper Lockyer home.

His defence team has rejected Ms Crawford was murdered.

The jury has already heard the couple had ongoing relationship issues, due to multiple instances of cheating carried out by Mr Crawford spanning several years.

In July 2023, after another revelation of infidelity, Mr Crawford was asked to leave their home and Ms Crawford had the locks changed, the jury has heard.

In the days following, the jury has heard Mr Crawford forcefully entered the property, sparking a verbal altercation which resulted in police attending.

Two of their children, Jessie and Jake Crawford, aged in their 20s, lived at the home at the time and gave evidence about this incident.

They also testified about the following period when their parents were separated, and when they reconciled some months later.

Jessie Crawford told the jury she stopped speaking to her father after discovering he was unfaithful and initially grew closer to her mother who was a "different person when she was away from him".

However, she said it was not long before her father returned to the home to help her mother with chores around the property.

"At first, he started showing up just to try and speak with mum, she didn't want that … but he continued,"she said.

"[Ms Crawford] said 'still don't want him here, but he's staying outside, he is doing something helpful, this doesn't change anything."

Jessie Crawford told the jury she noticed her parents speaking more frequently, and she believed her mother's "attitude started to change" and at the end of December.

"She started to go on dates again," she said.

Jessie Crawford told the jury on Mother's Day in 2024, three months after leaving the family home, Ms Crawford revealed she had reconciled with Mr Crawford.

She said her mother was "just that different person again" and she felt "quite hurt" she had been "pulled in again" by her father.

"She made promises she wouldn't let that happen again."

Jessie Crawford told the jury she felt like Ms Crawford was "picking our abuser" over her and her siblings.

"All she really said was 'it's hard for me too,'" she said.

Under cross examination she accepted she told police she believed her parents got back together much earlier, despite her father failing a polygraph test in counselling, which was one of several rules Ms Crawford set for him.

The jury has already heard Mr Crawford told police he believed his wife died while he was asleep, after she attempted to move the mower before their sprinkler system turned on.

Jessie Crawford told the jury she never saw her mother using the mower, and never saw it parked anywhere other than in the shed, however she acknowledged she had lived elsewhere between 2021 and mid-2023.

She also said in a statement to police, if there was an issue with the sprinklers, she believed her mother would go to the panel to check them, not the physical sprinklers themselves.

Her younger brother Jake Crawford told the jury during his parents' separation his mother had the house valued, and they had discussed moving.

"She was unsure if she could afford a house in Toowoomba that was big enough for the dogs or ... for us to visit, she was quite worried about the financial situation," he said.

Jake Crawford also testified about seeing his father come to the house while they were separated and on one occasion he overheard Mr Crawford call Ms Crawford a "psychopath".

"For setting up the cameras and other things she did," he said.

When he found out their parents were back together, Jake Crawford told the jury he was "distressed for her" and "scared for her safety," he said.

"None of us kids wanted her in an environment with my dad," he said while getting emotional.

Jake Crawford also testified he never saw his mother mow the lawn, and his father would never leave it out "because he said it would kill the grass".

He also said his mother did not know how to use the sprinkler system properly which had been set up by their father.

The trial continues.