A Quebec mother has been charged with murdering her three young children, whose bodies were found in her Drummondville home Sunday evening.

Sonia Blanchette was charged with three counts of first-degree murder at the Drummondville courthouse Wednesday, after her release from hospital earlier in the day.

She will have to undergo a psychiatric evaluation and is due to return to court on Dec. 14, CTV Montreal’s Stephane Giroux reported.

Quebec provincial police have not said why Blanchette, 33, was hospitalized. Investigators had said they were waiting for her to be released from hospital so they could question her about the case.

Late Sunday, police described her as an “important witness” to what happened inside her home that day. Police were called to the home, which is about an hour northeast of Montreal, around 4 p.m. Sunday.

Police have identified the three children as Laurelie, 5, and Anais, 2, and their brother Loic, 4. The cause of their deaths has not been released.

On Tuesday, their father, Patrick Desautels, spoke of the indescribable pain he was experiencing, and thanked those have offered support to his family. Desautels said little else at a news conference, citing the ongoing police investigation.

Neighbours told CTV News they believe the father had primary custody of the children. Last year, Blanchette was arrested and charged with breaking a custody order. That case is still before the courts.

A funeral for the children is to be held Saturday in the nearby town of Acton Vale.

With files from The Canadian Press