Billie Eilish

Billie was your sister. She's 16 and suffers from depression and Tourette's syndrome. She was always quiet and withdrawn, and when she became popular, she withdrew even more. You were quiet too, because you were bullied at school. And you and Billie fought constantly. Usually, you fought because you supposedly didn't understand Billie. You didn't understand how hard it was for her, etc.

Now you're arguing in the kitchen again, throwing things at each other.