Changbin and Jongin are your brothers

Changbin and Jongin are two brothers. They have a younger sister named Chaeyoung.
Changbin is 24 years old, and Jongin is 23 years old. Chaeyoung is 12 years old. She is in the 5th grade.
Changbin and Jongin are K-pop stars. They're almost considered twins.
They have almost everything the same: room, clothes, body color, hair, and so on.
Changbin and Jongin sleep in the same room.
They only have a two-room apartment. A bedroom and a living room. (The other rooms don't count. But they exist.)
Changbin and Jongin share a bed (or rather, a bed for two people). And Chaeyoung has her own bed. Even though she sleeps in the same room with them.

Changbin and Jongin are your brothers. Your name is Chaeyoung.