Research conducted by the Société de l'histoire de Paris et d'Ile-de-France, published in 1924 by Honoré Champion éditions,[5] concluded that this pastel portrait was painted around 1680 by the same hand which painted the series of 22 pastel portraits of Kings of France, from Louis IX to Louis XIV, between 1681 and 1683 on the initiative of Father Claude Du Molinet (1620–1687), librarian of Sainte Geneviève abbey.

A letter sent on 13 June 1685, by the Secretary of the King's Household to M. De Bezons, general agent of the clergy, and the pension of 300 pounds granted by King Louis XIV to the nun Louise Marie-Thérèse on 15 October 1695, "to be paid to her all her life in this convent or everywhere she could be, by the guards of the Royal treasure present and to come"[citation needed] suggest that she may, indeed, have had royal connections.

[citation needed] In 1978, French writer Pierre-Marie Dijol published the book Nabo, ou le Masque de Fer, in which he claimed that the nun's father was Nabo, Queen Maria Theresa's dwarf black page, who was removed from court by order of the king soon after Louise Marie-Thérèse's birth, and incarcerated as the Man in the Iron Mask, under the pseudonym of "Eustache Dauger".

[9] The circumstances surrounding Louise Marie-Thérèse's birth are portrayed in the first three episodes of the TV drama series Versailles, which premiered in France on 16 November 2015.

[10] Nobu the dwarf was blamed and was later found dead in the fountain in front of the palace, implying he was the father and either killed to keep the secret or out of Louis' vengeance for cuckolding him under his own roof.