Being an only child made me fascinated by siblings – and means I’ve had to learn to share my life

My debut novel is full of the brothers and sisters who were absent through my childhood

People often ask me about my brothers and sisters. They have read my debut novel, Girl A, and they expect to find my own family, encrypted in the fiction. There are seven siblings in the Gracie family in my book and between them there is caustic rage, begrudging respect, tenderness and cruelty. Too much love and too little.

I don't have any brothers and sisters. That's the thing about writers, I would like to reply, bolder than I really am. They make things up. Me, I'm nowhere to be found. Although that isn't quite the case.