WA mum who murdered, burned three kids to be sentenced

A mother who admitted stabbing, strangling and suffocating her three children before burning their bodies in a house fire in a West Australian town is set to learn her fate.

Margaret Dale Hawke, 36, is scheduled to be sentenced on Friday at the Supreme Court in Perth for three counts of murder and one count of criminal damage by fire.

She killed her 10-year-old daughter and two sons, aged seven and four months,  in the family's Port Hedland home in July last year.

The court previously heard Hawke strangled her daughter with an electrical cord and stabbed her eight times in her chest and heart.

Her seven-year-old son was found with three stab wounds to his chest and wounds on his neck from also being strangled.

Hawke admitted smothering her infant son before setting her home alight and walking into the street as it was engulfed by flames.

Prosecutor Justin Whalley SC told the court last month one witness described her as "really calm" as she watched it burn.

Another heard her say: "He's taken everything from me".

Mr Whalley said Hawke then screamed and cried, saying: "My babies, my babies ... You don't have to suffer anymore".

Members of the public tried to enter the home and save the children but it was too dangerous.

Hawke told police she didn't know of any other way to help her children before admitting to lighting the fire.

"My three babies ... I hurt my babies. I did it to my babies," she said.

Firefighters put out the blaze. Hawke's elder son's body was found on a mattress in a room at the front of the property. Her daughter and other son were found in a room at the back.

Hawke was taken to hospital and later admitted she had murdered her children.

"I don't know why I did what I did. Maybe to stop the pain in all of us," she told police in an interview after the incident, the court heard.

Mr Whalley said an arson investigation found the fire was deliberately lit with two ignition points in the house.

None of the children were found with soot in their respiratory systems indicating they likely died before the fire was lit.

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