The girl was convicted July 7 of three counts of making death threats.
She appeared again in court two days later and pleaded guilty to arson, joy-riding, mischief, attempted theft, possession of stolen property and breaching court orders.
These crimes were all committed after she was charged with threatening to kill her foster mother.
Crown counsel Paul Falvo told the court the girl threw around lit matches outside Mildred Hall school on June 9. She threw one match into an open window and the curtains caught fire.
Students stated the girl was throwing matches at them and said she was going to burn down the school.
Her lawyer, Jim Brydon, said the girl didn't intend to set the school on fire. When Judge Brian Bruser noted she did say she planned to burn the school, Brydon pointed out she also threatened to kill her principal and teacher, but never carried out those threats.
On June 14, the RCMP found the girl in the parking lot of the Gold Range Hotel driving a vehicle.
Three days later she was arrested at Corner Mart after she and three friends tried to steal a vehicle outside Le Frolic.
The girl was released by Judge Michel Bourassa soon after. During the bail hearing, Bourassa said the girl is not a "master criminal" and that social services has the power to do a number of things, including sending her to Winnipeg.
While waiting to be released in a holding cell, the girl scratched her name into the wall. After her name, she wrote "master criminal" and "Winnipeger." She also etched "shit happens."
Several days later, a Yellowknife resident was lying on his bed watching television when he looked outside and saw two girls in his driveway. The accused was in his car and kicked him in the leg when he tried to restrain her.
Brydon said the girl does not admit to trying to steal the car, but admits to "car hopping."
He explained this term means trying to steal small objects from cars. The girl will return to court on Aug. 5 after her assessment.