An Edmonton foster mother convicted of manslaughter in the death of a three-year-old boy in her care has been sentenced to six years in prison.

Lily Choy, 37, was found guilty by an Edmonton Court of Queen's Bench judge last month.

Choy had been sentenced to three years after she was found guilty of the same charge in 2008, a decision that was later overturned on appeal.

In announcing her sentence Friday, Justice Donna Reed ruled the penalty imposed by the first trial judge was "unfit" because she believed Choy's actions were "much higher on the blame scale."

The boy, who cannot be named under Alberta's Child, Youth and Family Enhancement Act, died of massive head trauma in January 2007 in Choy's Edmonton home.

The judge found that Choy abused the boy for a number of days leading up to the final assault that led to his death. The treatment was "callous and cruel," she said.

Choy spanked the child so hard it left bruises and left him in an unheated garage overnight wearing only a diaper. She finally lost control and used severe force to cause his fatal brain injury.

Crown reviewing sentence decision

The length of the sentence angered the boy's family.

"Six years is not fair," his aunt said. "She took this boy's life, my nephew's life, and the judge even said that she was guilty. The way I see it is that you take a life, you deserve life."

Crown prosecutor Allison Downey-Damato said the foster care system can't be blamed for what happened to the boy.

"It's very easy to levy blame at the foster care system and how it handled this case but the bottom line is this woman chose to do this to this child, and chose these actions and chose to have three more children placed in her care," Downey-Damato said.

"This was not something that was foisted upon her."

Choy's lawyer, Mona Duckett, asked the judge to impose a three-year sentence.

Downey-Damato asked for a sentence in the range of at least eight to 10 years. She backed away from her original recommendation of 12 to 16 years after considering appeal court decisions.

Downey-Damato told reporters outside the courthouse that the Crown may consider an appeal since the sentence was shorter than what was requested.

A jury convicted Choy of manslaughter in November 2008. Last year, the Alberta Court of Appeal overturned the conviction and ordered a new trial.