The Canadian Broadcasting Corp. reported Sonia Blanchette, 33, attended the hearing at the courthouse in Drummondville, Quebec, where the findings of her psychological evaluation conducted late last year were disclosed.
She has yet to enter a plea, but chose to have her case heard by a judge and jury, The (Montreal) Gazette reported. A preliminary hearing was set for March 28.
Blanchette is accused of killing her children, Anais, 2, Loic, 4, and Lorelie, 5, in early December at a Drummondville residence.
The Gazette said Blanchette appeared coherent while in the prisoner's box, though she tripped and seemed unstable as she entered the courthouse.
Blanchette, was going through a difficult custody fight with her ex-husband, Patrick Desautels.
A family friend said the children rarely visited Blanchette and only under supervision, QMI Agency reported.
The Gazette said the children's maternal grandmother was on hand they day they died but stepped out briefly -- and that is when the killings allegedly took place.