The gravesite of three young brothers who Ohio authorities say were killed by their mother now has a headstone with the image of a praying angel.

A Columbus company that makes cemetery markers donated the granite stone and put it in place Friday.

The owner told The Columbus Dispatch (http://bit.ly/1OYq5KE ) that the company wanted to something to honor the little boys.

Their mother has pleaded not guilty to aggravated murder charges in Bellefontaine, in western Ohio. Her attorney has not returned messages seeking comment on the case.

Authorities say Pilkington confessed to killing her 3-month-old son in August, a 4-year-old brother in April and a baby brother in July 2014.

Investigators say Pilkington was jealous of the attention her husband paid the boys.