Short answers, pulled from the story.
Louise d'Épinay (the 11th of March 1726 - the 17th of April 1783) was a French writer and saloniste connected to Rousseau, Diderot, d'Alembert, Baron d'Holbach, and Baron von Grimm. She won the Prix Monyon in January 1783 for Conversations d'Émilie and was cited by Simone de Beauvoir in The Second Sex as an example of noble expansion of women's rights during the eighteenth century.
D'Épinay furnished Rousseau with a cottage she named the Hermitage in 1756, in the valley of Montmorency, where he wrote La Nouvelle Héloïse. The two later quarreled and became implacable foes; in his Confessions, Rousseau insisted the inclination between them had been entirely on her side.
L'Histoire de Madame de Montbrillant is a pseudo-memoir begun by d'Épinay around age thirty and never published in her lifetime. After her death, a mangled version appeared in Paris in 1818 with all names changed; the first accurate edition was produced by George Roth in 1951 in three volumes under the title Les Pseudo-mémoires de Madame d'Épinay.
D'Épinay received the Prix Monyon from the Académie in January 1783, three months before her death. The prize honored the book most likely to benefit society, and the winning work was Conversations d'Émilie, a dialogue about the education of her granddaughter Émilie de Belsunce, originally published in 1774.
D'Épinay's friendship with Grimm began in 1755 and lasted until her death in April 1783. She collaborated on his private correspondence to European courts, and when he left France from 1775 to 1776, she continued the correspondence under Diderot's supervision.
Simone de Beauvoir cited d'Épinay in The Second Sex as an example of noble expansion of women's rights during the eighteenth century. The citation placed d'Épinay among noblewomen whose lives actively broadened what women of their era were permitted to do.