Happy Birthday, Billie Eilish!.br Billie Eilish Pirate Baird O'Connell turns 18 years old today.br Here are five fun facts br about the singer.br 1. Eilish has been writing music since she was 11 years old.br 2. She wears oversized br clothing to prevent br people from judging br her body.br 3. “The Office” is her favorite show.br 4. Eilish often collaborates with br her brother, Finneas O'Connell.br 5. She is the first br artist born in the br 2000s to have a br No. 1 album.