Sibéal has written for publications including The Guardian, fashion trend forecaster WGSN, Vogue.com and The Financial Times, where she was the resident philanthropy columnist for the How To Spend It section for six years. She studied Modern History at St Andrews and Quentin Tarantino film at Yale. Her bestselling debut Witch Wars has been translated into 10 languages so far and was shortlisted for the Sainsbury's Children's Book Award and the Waterstone's Children's Book Prize.