The father of two young boys, who died after their mother left them in a shower for 10 hours, has told a coronial inquest his former partner had bad sleeping habits but he never thought she was depressed.
The West Australian coroner is examining the deaths of Lochlan James Stevens, aged two, and Malachi Isaac Stevens, 10 months, who died in November 2008.
Their exhausted mother Miranda Hebble put them in the shower, after Lochlan had made a mess with his faeces, and closed the bathroom door.
She fell asleep or passed out and woke up about 10 hours later to find water overflowing from the shower and both boys dead.
Ms Hebble, then aged 22, was caring for her sons alone in Perth while the boys' father Christopher Stevens, then aged 23, was working on a fly-in fly-out basis.
The couple has since split.
Mr Stevens told the court on Tuesday that Ms Hebble was anaemic and struggled with her sleeping patterns.
Instead of napping when the children slept, she would watch cartoons, and at other times, she would sleep while the children cried or screamed, despite having a baby monitor.
Mr Stevens recalled an incident in February 2008 when Malachi was five weeks old and Ms Hebble left him in a car while she returned a DVD, prompting police to rescue the child and child protection authorities to be alerted.
He said he told Ms Hebble, "You don't leave him in the car for any period of time.
"Do you know what you've just done?
"We're all under the spotlight now."
The court previously heard Ms Hebble told police she left Malachi in the car because she could not carry him because she was so tired.
However, Mr Stevens said he did not think Ms Hebble was any "worse than normal" when she left the house that day.
He said she was just "a parent adapting to having two kids".
Mr Stevens said his former partner was a quiet, antisocial person who stayed in her shell.
"She likes being alone. She always has," he said.
"If there's any form of conflict she wouldn't go near it."
But Mr Stevens said he never thought Ms Hebble could be depressed because she would often shrug off any problems she had.
Mr Stevens said the first time he heard that Ms Hebble had failed to immunise Malachi was during the inquest.
The court heard a post-mortem examination of the boys could not reach a definitive conclusion but indicated drowning might have caused Malachi's death, while Lochlan might have suffered exhaustion, hunger and possibly hypothermia with exposure.
Drowning might also have contributed to his death, the court heard.
The inquest continues.