REGINA -- The mother of a six-year-old boy who was killed by an older child on a reserve in southern Saskatchewan described her son as a "beautiful baby boy" who liked to laugh and play.

Stacey Merk, 39, testified at a coroner's inquest Monday into the death of Lee Bonneau, who was found with head injuries in a wooded area on the Kahkewistahaw reserve in 2013.

Bonneau was in the care of the Ministry of Social Services and was last seen walking with an older boy outside the reserve's recreation complex while his foster mother was playing bingo.

Saskatchewan's child advocate determined that the 10-year-old boy who killed Bonneau had behavioural issues and probably shouldn't have been in the community unsupervised.

Because he was under 12, he could not be charged under the Youth Criminal Justice Act.

Coroner's counsel Sonya Guiboche asked Merk why social workers had intervened in her family. Guiboche said there were concerns about domestic violence in the home.

"Me or David never laid a hand on our son," Merk said.

Merk told the inquest she suffers from depression and has a learning disability. She said social services were involved in her life since Bonneau was born.

"They had some concerns about how I was going to be a good mom to Lee," she said.

The inquest is set to run for two weeks in Regina.