BARRIE, Ont. - The jury deciding the fate of a woman in Barrie, Ont., who drowned her two young daughters asked the judge Friday in the middle of their deliberations for an explanation of the phrase "morally wrong."

Elaine Campione, 35, is charged with two counts of first-degree murder in the deaths of her daughters Serena, 3, and Sophia, 19 months.

The defence concedes she killed the girls, but has urged the jury to find Campione not criminally responsible by reason of mental disorder.

The seven-week trial heard that Campione spent time in psychiatric wards, attempted suicide, had delusions that people were trying to kill her and steal the girls and exhibited bizarre behaviour including not letting one of her daughters touch anything red and claiming she saw aliens.

Campione believed the girls would only be safe in heaven, her lawyer Mary Cremer has told the jury.

The Crown contends Campione killed the girls days before a family court appearance so her abusive ex-husband couldn't get custody.

In its third full day of deliberations Friday the jury sent the judge a question, asking him to provide an explanation of the phrase "morally wrong," which he had used in his instructions to them earlier this week.

Justice Alfred Stong read the jury the Canadian Oxford Dictionary's definition of the word moral and reiterated what he said in his charge.

A person can be found not criminally responsible if a mental disorder rendered them incapable of knowing their conduct was wrong -- not just wrong in law, but wrong in the eyes of ordinary people, Stong said.

It's possible for a person to be aware that an action is ordinarily wrong, but the right thing to do in particular circumstances, he said. An example Stong gave is a man knowing it's legally wrong to do something, but because he is mentally ill and believes he is acting on orders from God his actions are not "morally wrong."

However, a finding of not criminally responsible is not available if the accused knew their actions were wrong in the eyes of society but decided to adhere to some other moral code.

The jury also asked about the phrase "balance of probabilities," and Stong said the onus is on the defence to prove Campione is not criminally responsible on a balance of probabilities, which is a lesser standard than the typical "beyond a reasonable doubt."

If the jury believes that Campione was more likely than not so mentally ill that she didn't know drowning her kids was wrong, they must return a verdict of not criminally responsible, Stong said.