Sarah Fermi was a life member of the Brontë Society, member of the Council as Publications Officer from 2008 to 2015 and frequent contributor to Brontë Studies, where she published pieces based on her original research into puzzles connected with Brontë biography.
Her interest in the Brontës was long and fruitful, maybe motivated by being one of three sisters herself. It was her reading of Edward Chitham's biography of Emily Brontë (and its many unanswered questions about Emily's life) that prompted her to more serious research.
Probably, her most famous and controversial theory was her suggestion that Emily Brontë had a relationship with a local boy named Robert Clayton, who in a certain way inspired much of Emily's poetry and even parts of Wuthering Heights. This theory was taken up by BBC Radio 4, and the play 'Cold in the Earth, and Fifteen Wild Decembers' by Sally Wainwright (who, ten years later, was to write and direct To Walk Invisible) was broadcast in 2006. Nevertheless, Sarah Fermi felt the need to explore her theory outside the boundaries of a radio play and she published a fictionalised account in the form of a diary: Emily's Journal was published a few months later.
Controversial it could be but not entirely crazy and thoroughly researched. It is worthwhile quoting from the Preface of the book in which Dr Patsy Stoneman writes:
Sarah's methods are those of the traditional historian: the patient and meticulous sifting of church records, land registers, wills and testaments, and, where they exist, letters and memoirs. By these means she has been able to solve problems which have lain uninvestigated since Gaskell's Life of Charlotte Brontë.