Hawking studied French and Russian at the University of Oxford, and then commenced work as a journalist. She has worked for New York Magazine and has written for the Daily Mail, The Telegraph, The Times, and the London Evening Standard. She has also worked as a radio journalist.

Hawking has written two novels: Jaded (2004) and Run for Your Life (2005) (also published as The Accidental Marathon).

In 2007, she published George’s Secret Key to the Universe, an adventure story about a small boy called George who finds a way to slip through a computer generated portal and travel around the solar system. Written with her father, Stephen Hawking and his former Ph.D. Student, Christophe Galfard, George’s Secret Key has been translated into 38 languages and published in 43 countries. George’s Cosmic Treasure Hunt, a look across the universe for signs of life followed in 2009. Their third children's story will be about "What happened at the Big Bang?"

In April 2008, Hawking participated in NASA’s 50th Birthday lecture series, contributing a talk on children and science education. Based on her experiences in touring worldwide with George’s Secret Key, giving talks for children on physics and astronomy, the lecture highlighted the need to engage children in science at an early age.Hawking won the Sapio Prize for popularizing science, awarded in Rome in October 2008.She is vice president of the National Star College, a residential foundation which provides care and education for young adults with complex and multiple disabilities and a Friend of the ARC. Hawking is also an FRSA.

Hawking is an administrative staff member of the Autism Research Centre (ARC), which is situated within the School of Clinical Medicine in the Department of Psychiatry, Section of Developmental Psychiatry, at the University of Cambridge. She is in charge of Friends of the ARC. She became interested in autism when her son, William MacKenzie Smith, was diagnosed with the disorder.

These are co-written with her father Stephen.

• George's Secret Key to the Universe, (Random House, 2007) ISBN 9780385612708
• George's Cosmic Treasure Hunt, (Simon & Schuster Children's Publishing, 2009) ISBN 9781416986713