The blaze began just after 3:30 a.m. PT in View Royal and quickly engulfed the basement where the girl's bedroom was located.
Firefighters rescued the girl's great-grandmother from the basement and found the grandmother unconscious at front door of the home.
Fire Chief Paul Hurst said the girl, who was not breathing and did not have a pulse, was rescued from the main floor hallway.
"As we understand, she came upstairs away from the fire," Hurst said.
"Probably disoriented from smoke and high heat, [she] collapsed in the hallway."
Hurst said temperatures had reached 700 degrees inside the single family home, when firefighters arrived on the scene.
"The damage is extensive in the house. The bottom floor is pretty well destroyed, with extensive heat and smoke damage to the second floor," he said.
The girl was resuscitated on the front lawn of the house and together with her grandmother, was flown to B.C. Children's Hospital. The girl's great-grandmother is receiving hospital treatment in Victoria.
On Thursday afternoon, Hurst said the fire was the result of combustible materials stored too close to a baseboard heater in the laundry room.
"Obviously, the fire went went undetected for some time," he said.
"And then once it broke through the laundry room door, it spread throughout the house rapidly."
Hurst said there was a smoke detector in the house, but fire investigators cannot determine if the device was working at the time of the fire.