But Allyson McConnell's defence lawyer has told a judge the depressed and suicidal woman has already served nearly two years in custody and should return to her home country a free woman.
"She has paid and will continue to pay an incredible price because of what she was driven to do by a mental disorder," Peter Royal said in Wetaskiwin court Wednesday.
McConnell, currently on suicide watch while in custody at Alberta Hospital, testified during her trial that her future will consist of more suicide attempts because she does not want to get well.
Justice Michelle Crighton said she will hand down the sentence June 4.
The judge convicted the 33-year-old woman last month of manslaughter. McConnell was originally charged with second-degree murder but Crighton ruled there was a "black hole" in the evidence and no one knows what the woman's mental state and intent were at the time she killed her children.
Court heard McConnell and her husband were in the middle of a bitter divorce and she wanted to take their children back to Australia.
On Feb. 1, 2010, she drove from the family's home in Millet north to Edmonton, parked her car at a toy store and jumped off an overpass onto a busy freeway.
When police called her husband to say she was in the hospital with broken bones, he wondered where the children were and quickly drove home from work. He found 10-month-old Jayden and two-year-old Connor floating in the tub.
"I have flashbacks of the feel of their dead bodies, the smell of them being dead," Curtis wrote in a victim impact statement given to the court. "To come home to find my kids left to rot by the person I loved and trusted more than anyone else has made it so hard to trust anyone again."
Court also heard Allyson McConnell remembers nothing about the days before she jumped off the overpass and did not know her children were dead until her mother and sister told her as she lay in her hospital bed. The news drove her into hysterics.
A psychiatrist testified the woman likely meant to kill herself but was so close to her children that she considered their lives extensions of her own. It was also revealed that McConnell has a history of depression and suicide attempts that began when she was impregnated by her father at 15.
Crown prosecutor Gordon Hatch said the boys died horrific deaths and must have struggled and fought against their mother as she held them under water for three to 10 minutes each.
He said evidence shows McConnell killed her infant son first and the toddler, old enough to know what was happening, must have been terrified as he watched his brother die next to him.
Hatch said McConnell had several minutes to change her mind, release her grip on the boys and call for help. They likely would have survived.
"It's not a momentary lapse in judgement like shaking a crying baby," he said. "Its a clear decision to end a life. It's a decision she made twice."
Hatch recommended the judge give McConnell 1 1/2 times credit for the time she has spent in custody, cutting his recommended 12 years down to about nine.
Royal said his client deserves two-to-one credit, amounting to 4 1/2 years of time already served.
He said the Canadian government, days after the verdict, served McConnell with deportation papers and officials in Australia support her return, even if it's to serve a prison term there.
Curtis McConnell's mother, Audrey McConnell, told the court she wants the case to be over.
"Please, I'm begging you, can this legal nightmare be over so we can mourn our precious babies in peace," she said, choking back sobs as she read her victim impact statement to the judge.
She spoke about how she went to bed clutching their shirts after they died. And how the family took candles to their graves to sing Happy Birthday.
She said one day she cleaned her patio doors but realized too late that she was wiping away Connor's sticky fingerprints.
"I cried for days knowing there would be no new ones. I wish I had left them there."