[2] Rappaport was born Helen Ware in Bromley, grew up near the River Medway in North Kent and attended Chatham Grammar School for Girls.

[8] She became a full-time writer in 1998,[5] writing three books for US publisher ABC-CLIO including An Encyclopaedia of Women Social Reformers in 2001, with a foreword by Marian Wright Edelman.

It won an award in 2002 from the American Library Association as an Outstanding Reference Source and according to the Times Higher Education Supplement, 'A splendid book, informative and wide-ranging'.

[11][12] Mary Seacole features in Rappaport's 2007 book No Place for Ladies: The Untold Story of Women in the Crimean War which was praised by Simon Sebag Montefiore as being 'Poignant and inspirational, well researched yet thoroughly readable' and also received positive reviews in The Times and The Guardian.

[16] Her 2010 book, Beautiful For Ever describes the growth of the Victorian cosmetics industry and tells the story of Madame Rachel who found both fame and infamy peddling products which claimed almost magical powers of "restoration and preservation".