Sanditon, composed in the early months of 1817, differs from the other texts covered by this book in that it was the work of a woman who was finally a published novelist, and one who had enjoyed some success, both popular and critical. Jane Austen had eventually brought out in quick succession four novels: Sense and Sensibility (1811), Pride and Prejudice (1813), Mansfield Park (1814) and Emma (1815). By early August 1816, she had completed Persuasion. According to Kathryn Sutherland, the manuscript of Sanditon thus shows ‘the working methods of a confident and experienced professional novelist’, while Linda Bree and Janet Todd observe that Sanditon is ‘neatly divided into chapters’ and was written in larger booklets than the earlier manuscript works. By comparison with The Watsons, there are no interpolated pages or inserted material, and much of the text contains little correction. This last circumstance might speak to Austen's growing confidence in her writing, but it is at least partially explained by the brief period of composition: the first page of the first booklet bears the date 27 January 1817, the first page of the third is marked ‘Mar. 1’, and at the end of the MS appears the date ‘March 18’. There is no evidence that, as her final illness advanced, Austen was able to revisit the text after 18 March: she died exactly four months later, on 18 July.

Mary Lascelles commented long ago that had any of the published novels broken off at the same point as Sanditon ended (part-way through Chapter 12), it would not ‘have left us in such uncertainty as to the way in which it was going to develop’. On the other hand, whereas in the cases of ‘Catharine’, Lady Susan and The Watsons, it can be argued that Austen abandoned her work because of problems inherent to what she had already written, the incompleteness of Sanditon has always been attributed to the deterioration of the author's health. It is assumed that had Austen lived, she would have finished the novel. As a result, a combination of factors – Austen's elusive intentions for this fragment, its status as her last substantial work, and the belief that she would have completed it had she survived – means that Sanditon is a text whose unanswered questions have especially fascinated many readers and critics.