The memoir, The Sibling, is based on the author’s experience growing up as the sister of a brother who was diagnosed with autism in 1975, a new term for the time, and how her misfit family navigated the early years of diagnosis. After writing more than 40 memoirs and biographies for others as a ghost writer, Jools decided it was about time she wrote her own, and after meeting other Siblings at an event, decided the time was now.

The Sibling is written from a childhood perspective. A solo child whose world is irrevocably altered by the arrival of a changeling, a baby brother who is different from other brothers. The book is about their childhood, growing up in a close, yet separate, relationship during the 1970s and ‘80s. Autism is sometimes described as sensory overload, so the book is thematically organised into that area of experience; Sight and sound - holidays and rain on the caravan roof. Taste - food, home for lunch. Touch and smell - school and play, relationships, diagnosis, the psychologist and a sibling leaving home.

The memoir navigates Jools' Northern, working-class background and misfit family, exploring sibling identity and definition through shared family life. It is a book of place, class and time, written with humour and heart.