The grandmother of a baby who died in foster care last year released 350 balloons Friday on what would have been the child's second birthday.

Marilyn Koren's granddaughter Delonna Sullivan was four months old when she died on April 11, 2011, six days after she was removed from her home in central Alberta and placed in foster care.

Delonna Sullivan died on April 11, 2011, six days after being placed in foster care. (Courtesy of Jamie Sullivan )

Twenty-nine children have died while in government care since 2007. Koren released the balloons in front of the Leduc courthouse in their memory.

"After my granddaughter's death I had made myself a promise that I would do anything and everything within my power to save another child's life," Koren said.

Delonna was taken from her mother Jamie Sullivan by two social workers and an RCMP officer who had come to apprehend the children of an unrelated person who also lived in the home.

They ended up placing Delonna in foster care believing there was "disharmony in the home." Documents obtained by CBC News show that social workers believed Sullivan had an alcohol problem, an allegation she denied.

Since then, Koren and Sullivan have waged a battle to find out why the little girl died. They went to court to have a publication ban lifted on Delonna's identity so they could go public with her name and photographs.

They requested medical records that showed Delonna died as a result of cardiac arrest, even though an autopsy report recorded it as a sudden, unexplained death.

Koren wants the child welfare system to be more open and accountable.

"I made a commitment that, no matter what, I would do everything and anything within my power, to save another child's life through the advocacy work ... that I've been doing," she said. "And that another family doesn't have to suffer."