Pinborough was born in Buckinghamshire in 1972. Because of her father's career as a diplomat, much of Sarah's early childhood was spent travelling in the Middle East. From the ages of eight to eighteen Sarah attended boarding school, which she claims has influenced her writing.

Pinborough trained to be a secondary school teacher after a brief marriage, while still writing her novels. She taught for three years at the Lord Grey School before moving onto Lea Manor High School in Luton. Pinborough also taught at Walton High, Milton Keynes Afterwards.

Sarah was briefly seen on the Sci-fi Channel giving her opinions of the horror writer Stephen King.