Gran warned Child Safety before girls died in hot car

Their mother, Kerri-Ann Conley, had left them in the car outside her home since 4am after returning from a drive to a friend's place and using the drug methamphetamine.

Darcey "had bruises ... nappy rash like I have never seen before", Sandra Cowan testified. (Darren England/AAP PHOTOS)

Conley pleaded guilty in February 2023 to two counts of manslaughter and was sentenced to nine years' jail to be eligible for parole in November 2024.

A five-day inquest opened in Brisbane on Monday and heard from Deanne Power, the mother of Darcey's father, Peter Jackson.

Ms Power said she had warned Queensland's Department of Child Safety more than a year before the girls' deaths Conley was possibly using cannabis and meth while keeping Darcey in unsanitary living conditions.

"I said that (Darcey) was in danger living with her mother," Ms Power said.

She said before the girls' deaths, child safety workers were played a phone message in which Conley admitted falling asleep on the couch and leaving Chloe in the car all night.

Some of the issues the inquest will examine include the appropriateness of the response by the Department of Child Safety and adequacy of its policies and procedures before the girls' deaths.

Tamra Jackson said she became angry when the department returned Darcey to Conley's care. (Darren England/AAP PHOTOS)

Peter Jackson, who last year filed personal injury and negligence lawsuits against the Queensland government, had his testimony rescheduled to Tuesday because of its significant expected length.

Childcare educator Sandra Cowan testified that Darcey was not meeting her developmental milestones in terms of talking but Conley had told her she was not concerned.

"(Nine days before her death) Darcey had bruises ... nappy rash like I have never seen before ... it was very red, very inflamed, a bit scabby," Ms Cowan said.

Darcey and Chloe were left to die from fatal overheating after her mother had taken them in the car at 11.30pm to visit a friend's home.

Joanne Chilcott, whose son was in a relationship with Conley in the lead-up to the girls' deaths, said their mother had gone for late night drives "a few times" previously with Darcey and Chloe in the car.

Kerri-Ann Conley pleaded guilty to two counts of manslaughter and was sentenced to nine years' jail. (Supplied/AAP PHOTOS)

Mr Jackson's cousin Tamra told the inquest she became angry when the department decided to return Darcey to Kerri-Ann Conley's care.

"Previously Kerri-Ann had admitted she was buying urine online and doing false drug tests. She said this in front of (a child safety support worker) but nothing was done," Ms Jackson said.

Ms Jackson said she had shown police a text message from the same child safety support officer that told Kerri-Ann Conley to "stay off that s*** if you can".

"They clearly knew she was using," she said.

Ms Jackson said the Department of Child Safety would not grant custody of Darcey to Peter Jackson even though staff treated him like the two girls' father as his name was not on Darcey's birth certificate and he did not complete a DNA test.

Deborah Jackson (second left) said Conley left the hospital after Darcey's birth to use drugs. (Darren England/AAP PHOTOS)

Under questioning from the department's barrister Timothy Ryan, Ms Jackson agreed she did not tell other and more senior Child Safety staff about the text message telling Conley to stay off drugs.

Ms Jackson also agreed Darcey was returned to Conley's care with a timetable for friends and family to check up on her via phone and in person.

Darcey's great aunt, Deborah Jackson, told the inquest Conley had been leaving the hospital after Darcey was born to use drugs in her car and had to be let back in by security guards.

"One time she went to her drug dealer and did not get back to the hospital until 3am," Ms Jackson said.

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