CALGARY 芒鈧珺次元官网网址� A Calgary woman has admitted to drugging her nine-year-old daughter, then setting fire to the vehicle her child was in.

Laura Coward, who is 50, pleaded guilty Thursday to second-degree murder in the death of Amber Lucius.

Coward was originally charged with first-degree murder and was to go to trial next week.

She is to return to court for sentencing March 3.

Amber was reported missing Aug. 31, 2014 and her mother was arrested two days later near Sundre standing outside a burned vehicle where her daughter's body was discovered.

In an agreed statement of facts, Crown prosecutor Mac Vomberg told court that Amber was visiting Coward for the weekend. Her mother told her they were going to Tim Hortons and then to "look at the stars."

Coward gave Amber a toxic but non-lethal dose of a prescription sleeping medication.

"The accused admits that sometime later she woke up," Vomberg said.

"She checked Amber and mistakenly thought she had died. The accused panicked."

Vomberg said Coward filled the vehicle 芒鈧珺次元官网网址� with Amber unconscious in it 芒鈧珺次元官网网址� with paper and plastic totes and set it on fire with a propane torch before closing the door.

"She then left the vehicle scene until an undetermined time after the fire had self extinguished and Amber had died," said Vomberg.

"The accused admits that she intentionally caused the death of Amber but not in the manner that she expected."

Vomberg said an autopsy suggested the girl died of a combination of hypothermia, smoke inhalation and carbon monoxide toxicity.

A police officer who came upon the burned vehicle saw a handwritten note on the outside of the driver's door that read: "Help me. It was an accident. Locked keys in."

Vomberg assured Justice Scott Brooker that the plea to the lesser charge had been discussed with the little girl's family.

"It would be fair to say sir that it's a difficult period and it's a very difficult situation for them. They do understand the reasons for the Crown resolving the case in this manner."

Earlier documents described a bitter divorce between Coward and the girl's father, Duane Lucius, and a custody tug-of-war over their daughter that continued up until the girl was found dead.

Her father alleged in a court affidavit when Coward filed for divorce in December 2007 that his wife wasn't the same after the birth of their daughter.

"She would anger easily and we would argue often," he said.

The couple separated in October 2007 after three years of marriage. Lucius, 44, worked in construction and Coward had a job as an accountant.

She also has an older daughter from a previous marriage.

The couple initially shared joint custody of both girls, but the children primarily lived with Coward. The woman claimed in affidavits that her estranged husband often didn't take medication for his epilepsy and was prone to outbursts. She said she feared for her safety and the safety of the girls.

In several other affidavits, Lucius alleged his wife was using his epilepsy as an excuse to deny him visits with the children. He said he hadn't had a seizure since he was 18.

He also alleged that she refused to grant numerous court-ordered visits. He provided a doctor's assessment that Coward was excessively possessive and protective of Amber.

A letter on the court file from a daycare operator in Vauxhall, Alta., described Coward as an "excellent mother" and called Amber a "cheerful and friendly little girl."

Affidavits in the court file contain allegations not necessarily proven in court.

In June 2013, a judge named Lucius as Amber's primary caregiver and she moved back to his parents' farm with him. Coward and the other child moved to a nearby rural property to be closer to Amber.

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Bill Graveland, The Canadian Press