Sonia Blanchette. (Eric Beaupre/QMI Agency) Mom accused of murdering her three kids declared fit to stand trial Hundreds attend funeral of three siblings in Quebec Mother of three drowned kids faces murder charges Drowning deaths 'impossible to explain': Father Bodies of 3 kids found in Que. town

DRUMMONDVILLE, Que. — A depressed 33-year-old divorcee who lost custody of her three young children and allegedly kidnapped one of them is now considered an important witness in their drowning deaths.

The grandmother found the bodies of Laurelie, 5, Loic, 4, and Anais, 2, in a top-floor apartment in this city east of Montreal on Sunday.

Sonia Blanchette, who had lost a 2 1/2-year custody battle, was taken to hospital in shock.

Police said the mother is an "important witness."

A neighbour who gave her name as Veronique said Blanchette was depressed and rarely saw her children, who lived with their father.

"I heard the grandmother's screams when she went in and found the children," Veronique said.

The father arrived after he was alerted by the grandmother. He later left the area, overcome with emotion.

Several sources said Blanchette was only allowed to see her children during supervised visits.

Last December she was charged with kidnapping her youngest child, who was 14 months old at the time.