Louise Marie Madeleine Fontaine
Louise-Marie-Madeleine Guillaume de Fontaine (after marriage known as Madame Dupin; 28 October 1706 – 20 November 1799) was a French "saloniste".
Louise of France (1737–1787)
After her renunciation, Louise came to be in a far more influential position of status than what she had been as the youngest of princesses, and she was reportedly consulted as an authority figure by the king her father, the princes, the ambassadors, the bishops and the archbishops. Her relationship to her sisters never quite recovered after she left court: "The three sisters who were left never pardoned Madame Louise for concealing her intentions, and though they went to see her sometimes, it was with no feelings of pleasure or friendship. Her death was no grief to them." Like her sisters, however, she opposed the wedding of her nephew the Dauphin to Maria Antoinette of Austria, this marriage having been concluded by Choiseul, whom she detested because of his banishment of the Jesuits. This confidence in her counsel did attract attention by contemporaries, "The retirement of Madame Louise, and her removal from Court, had only served to give her up entirely to the intrigues of the clergy. She received incessant visits from bishops, archbishops, and ambitious priests of every rank; she prevailed on the King, her father, to grant many ecclesiastical preferments, and probably looked forward to playing an important part when the King, weary of his licentious course of life, should begin to think of religion. This, perhaps, might have been the case had not a sudden and unexpected death put an end to his career. The project of Madame Louise fell to the ground in consequence of this event." 
While the intrigues of her sisters "Mesdames" made them exposed to some hostility, Louise was, despite her political activity, not exposed to the same feelings, though "only her habit saved Sister Therese from being included in this unpopularity."