A child called out for a glass of water as smoke reached their bedroom after their mother allegedly set the house on fire, the ACT Supreme Court has heard.

Key points: The woman, who faces two charges of attempted murder, has been denied bail

The woman, who faces two charges of attempted murder, has been denied bail She is accused to setting her house on fire in a bid to kill herself and her two children

She is accused to setting her house on fire in a bid to kill herself and her two children Prosecutors say the risk of her harming her children or ex-husband is too high to release her

The Canberra woman is accused of trying to kill herself and her two then-primary-school-aged children by igniting their home.

She lost her bid for bail on Friday after claiming her ill health placed her at greater risk of harm if she caught COVID-19 while in detention.

The woman was charged with two counts of attempted murder after firefighters pulled the three, then unconscious, from their home in Canberra's south last year.

She and one of the children were taken to Sydney for specialist medical treatment.

The woman, then aged 47, was arrested there and extradited back to Canberra.

Some of the case's details have been suppressed to protect the children's identities.

Her lawyer, Stephen Whybrow, told the Supreme Court the woman suffered from asthma and type 2 diabetes and the coronavirus pandemic put her at greater risk.

He said that, although there were no cases of the disease in prison at present, the woman could be endangered if that changed.

'Stay calm and lie on your bed'

Justice David Mossop dismissed the application, saying the woman posed an unacceptable risk to her children and her ex-husband.

The judge said that, when one of the children asked for a glass of water, the mother allegedly told them to "stay calm and lie on your bed" as smoke engulfed their home.

Justice David Mossop said the mother was unlikely to be deterred by bail conditions. ( ABC News )

He said she had laid down on the floor of her children's bedroom and cried after allegedly setting alight a couch and linen cupboard.

"Bail must be refused whether or not there are special circumstances," Justice Mossop said.

"A person who was willing to sacrifice her own life is unlikely to be deterred by conditions of her bail."

The defence relied on material from other courts raising concerns for people in custody who could face increased risks.

But prosecutor Anthony Williamson said there was no evidence the virus would put the woman at greater risk, as the ACT's jail had established safeguards against the infection.

The woman wiped away tears as Mr Williamson raised concerns about the victims.

"This is effectively a murder-suicide that was stopped," the prosecutor said.

He added that, if the prospect of the woman losing her own life hadn't been enough to stop her committing the alleged crime, no bail condition could mitigate the risk.

Mr Williamson also told the court that the children's father was petrified at the thought she might be released.