Melanie Watson, best known for her role on the classic sitcom Diff’rent Strokes, has passed away at the age of 57.

Watson died on Friday, Dec. 26, in Colorado Springs, Colorado, according to a report from TMZ. Her brother, Robert Watson, shared that she had been hospitalized prior to her death and that her condition worsened during her stay. He noted that she lived longer than many expected given her medical challenges.

Born with osteogenesis imperfecta — commonly known as brittle bone disease — Watson used a wheelchair throughout her life. The genetic disorder affects connective tissue and causes bones to fracture easily.

Watson appeared in four episodes of Diff’rent Strokes as Kathy Gordon. The long-running NBC sitcom starred Gary Coleman and Todd Bridges and aired from 1978 to 1986. After her time on the show, Watson stepped away from acting.

She later dedicated her life to advocacy and service, founding Train Rite, an organization focused on training shelter dogs to assist people with disabilities. She served as the nonprofit’s executive director, according to her IMDb profile.