In the novel Hallowe'en Party, Harriet Leaman is a cleaning in the village of Woodleigh Common. She is described as being a "neatly attired woman of middle age".
Mrs Leaman's husband passed away about five years before the events of the novel. After that, she began working as a cleaning woman for ladies in Woodleigh Common. In the past, she had worked for Mrs Llewellyn-Smyth, at the Quarry House.
Shortly before she died, Mrs Llewellyn-Smyth had called Mrs Leaman and a gardener James Jenkins to her room and asked them to witness a codicil to her will. On leaving the room, she looked back through the half closed door and saw that Mrs Llewellyn-Smythe hid the codicil inside a copy of Enquire Within Upon Everything. Later, on a day when Mrs Llewellyn-Smythe had gone out, Mrs Leaman sneaked into her room, took the book out and read the codicil.
She was surprised when lawyers later pronounced the codicil a forgery because she had witnessed it. She did not speak out because she did not think she had done anything wrong and in any case did not want to get entangled with the law.