My brother has been struggling with medical problems for most of his life. I was five years old when Jason was born, and I thought he was perfect. He was my own personal, real-life baby doll. When I heard him crying, I would climb into his crib to comfort him. As I grew more confident in my sisterly abilities, I figured out how to lift him out of his crib so I could carry him to my room.

Sometime between his first and second birthdays, Jason got sick. He had a brain tumor, my parents said. I now know that it was a Medulloblastoma. Six-year-old me didn’t understand that. Six-year-old me only…