All will spend time in the community under supervision, when they are released from jail.
The teens played "Russian roulette" with people's lives in targeting the house in Hobbema, Alta., and their actions constituted "domestic terrorism," Judge Geoffrey Ho said during sentencing in provincial court at Wetaskiwin.
Ethan was sleeping in his father's home on the Samson Cree First Nation early on July 11, 2011, when bullets sprayed the home. He was shot in the head and died.
According to an agreed statement of facts, the oldest youth, who was 17 at the time of the incident, used a rifle to fire a shot over the house.
He handed the gun to the other boys, then 16 and 13, who fired two shots each into the house.
The teenage boys, who cannot be named under the Youth Criminal Justice Act, pleaded guilty to manslaughter in November.
Crown prosecutor Trent Wilson had asked for the maximum sentence allowed under the Youth Criminal Justice Act — two years in custody and one year of community supervision.
In March, court heard all three of the convicted teens have lived troubled lives fuelled by drugs, alcohol and membership in gangs on the reserve.