The story of Mme de Montolieu's flirtation and playing at courtship with Gibbon, his role in the writing and production of Caroline de Lichtfield, and their continuing real later friendship are all alluded to by him in Volume 3 of The Letters of Edward Gibbon, ed. J. E. Norton (London: Cassell, 1956, 3 vols): 1) A full portrait of Gibbon's time among these women which probably includes details of emotion and memory connected to Montolieu, October 22, 1784: No. 623, Vol 3, pp 13-14 (he is 47, she is 33), from which I quote: "I have discovered about half a dozen Wives who would please me in different ways and by various merits; one as a Mistress (a Widow vastly like the Eliza; and if she returns I am to bring them together ..." The Eliza is Lady Eliza Foster who became mistress to Devonshire after becoming governess to his daughter; and of whom Gibbon said she was so seductive a old powerful male sitting on his woolsack in front of all the Parliament who get off to follow her beckoning in public if she did so beckon); 2) We see how the novel figured into their relationship: January 20, 1787, No 642, Vol 3, p 62 (he is 49, she is 35): "Has Mylady read a novel entitled Caroline de Lichtfield, of our home manufacture; I may say of ours, since Deyverdun and myself were the judges and patrons of the Manuscript. The author who is since married a second time (Madame de Crousaz, now Montolieu) is a charming woman. I was in some danger."; 3) He singles out Mme de Montolieu as someone Catherine de Severy should tell he remembers her, May 23, 1788, No 687, Vol 3, p 106 (he is 51; she is 37); 4) the story of his kneeling in play to a woman happened but with Duchess of Devonshire, October 12, 1792, No 813, Vol 3, p 278 (he is 55; she is 41); 5) Evidence of continuing mutually supportive friendship, November 8, 1792, No 816, Vol 3, p 288 (he is 55; she 41): "Your note has been communicated to Madame de Montolieu; but as she is engaged with a dying aunt, I have not yet seen her."
See also J. H. Adeane, ed. The Girlhood of Maria-Josepha Holroyd. (London, New York and Bombay: Longmans: Green & Co), 1896 (for a portrait of Isabelle when "courted" by Gibbon); H. M. Beatty, "Gibbon and the Duchess of Devonshire," Times Literary Supplement, 772 (2 November 1916), p. 525 (a letter in which the correspondent cites earlier sources in which Madame de Montolieu is quoted as having emphatically denied that Gibbon "threw himself at my feet ... the whole story is an invention"); Amanda Foreman, Georgiana, Duchess of Devonshire. New York: Random House, 1998 (for a portrait of Lady Eliza Foster); Edward Gibbon, Le Journal de Gibbon à Lausanne, ed. Georges Bonnard (Lausanne: F. Rouge & Cie, 1945; Edward Gibbon, An Autobiography, as originally edited by Lord Sheffield, with an introduction by J. B. Bury (London: Oxford University Press,1907); D. M. Low, Edward Gibbon (New York : Random House, 1937), pp. 307-309; George Sampson, "Gibbon's Proposal", Times Literary Supplement, 2262 (9 June 1842) (a letter in which the correspondent complains about the continuaation of the "apocryphal anecdote; but Sampson repeats the story that Madame de Genlis invented the story to annoy Montolieu); and M. [William] and Mme Sévery, La Vie de Société dans le Pays de Vaud à la fin du dix-huitième siècle: Salomon et Catherine de Charrière de Sévery et leurs amis, 2 Vols. Lausanne and Paris, 1911; reprinted Genève: Slatkine, 1978 (2 vols).