This is a biographical book. Modelled on Madame de Genlis's Adèle et Théodore (1782) and Tales of the Castle (1785), both of which have frame stories and a series of inset moral tales, Original Stories narrates the re-education of two young girls, fourteen-year-old Mary and twelve-year-old Caroline, by a wise and benevolent maternal figure, Mrs. Mason. (Wollstonecraft probably named these characters after people in her own life. She became acquainted with a Miss Mason while teaching in Newington Green, whom she greatly respected, and she taught two girls named Mary and Caroline while she was a governess for the Kingsborough family in Ireland. Margaret King, who was greatly affected by her governess, saying she 'had freed her mind from all superstitions, later adopted 'Mrs Mason' as a pseudonym.) After the death of their mother, the girls are sent to live with Mrs. Mason in the country. They are full of faults, such as greediness and vanity, and Mrs. Mason, through stories, real-world demonstrations, and her own example, cures the girls of most of their moral failings and imbues them with a desire to be virtuous. Mrs. Mason's amalgam of tales and teaching excursions dominates the text; although the text emphasizes the girls' moral progress, the reader learns very little about the girls themselves. The work consists largely of personal histories of people known to Mrs. Mason and of moral tales for the edification of Mary and Caroline and the reader.