Diane Margaret Pearson was born on 5 November 1931 in Croyden, London, England, daughter of Miriam Harriet Youde and William Holker. During her childhood, she often visited her grandparents in a village on the Surrey/Kent borders. She attended Secondary School in Croyden. She became in 1975, the second wife of the Irish actor Richard Leech (McClelland).
At 16, Diane started her career in publishing with Jonathan Cape Ltd, and she has been Senior Editor for Transworld Publishers for more than 35 years. In 1994 she won the British Book Award for Editor of the Year. As Diane Pearson she has published six historical romance novels and several short stories. She also was the President of the Romantic Novelists' Association from 1986 to 2011, when she retired. A widow since 2004, she lived in her native London until her death on 5 August 2017.