A heartbroken Calgary family has finally learned how their young daughter died while in the care of an unlicensed dayhome, after the owner decided at the last minute to plead guilty and admit what really happened.

Eighteen-month-old Ceira McGrath died in November 2015 while in the care of Elmarie Simons, 59. After the girl’s death, Simons told CTV Calgary that Ceira had been fussy that day and refused to nap in a playpen, so she placed the girl in a car seat – unaware, she said, that the Canadian Pediatric Paediatric Society advises against such a practice. She said Ceira simply never awoke.

A few months after the girl’s death, her mother Tanya Gladwell told CTV Calgary that it was hard to grieve with so many unanswered questions about how their perfectly healthy child could have died in her sleep.

They said Ceira’s twin brother Colby, who had also been in Simons’ care that day, was still struggling to understand where his sister had gone.

On Monday, Simons was due to begin a 10-day trial for criminal negligence causing death but decided at the last minute to plead guilty. In an agreed statement of facts, she explained to the court what really happened.

Simons revealed that she wanted to go out to run errands on the day Ceira died, so she strapped the girl into a car seat. The car seat was too small for the toddler and the straps between the girl’s legs wouldn’t fasten, so Simons simply buckled the chest strap.

Simons then placed Ceira in the car seat inside in a closet, alone, and left the house for five hours, stopping in at Walmart and McDonalds. Even when she returned, Simons didn't check on Ceira until she found her hours later, unresponsive. The girl had died from asphyxiation from the car seat straps.

Ceira’s father told reporters outside of court Monday that he was disgusted by what he heard.

“It’s absolutely horrific, it’s disgusting. I don’t know who could do this, especially a person we trusted,” Ryan McGrath said.

McGrath said he still hasn’t been able to get over his daughter’s death.

“It’s all I can think about. It’s why I've struggled falling asleep for the last two and a half years,” he said.

McGrath said the family had been on wait lists for licensed dayhomes but knew it would be a long wait with twins. So they chose to use Simons’ dayhome, which they said came highly recommended to them.

He said his one comfort in hearing Simons’ version of events is knowing that his son didn’t watch his sister die.

“I thought at one point Colby was witness to it, so if there's any silver lining it’s that he wasn't also there. I still have questions where our son was for five hours,” he said.

The family is expected to give its victim impact statement before Simons is sentenced.

With a report from CTV Calgary’s Ina Sidhu