Task: Question Answering
Input (English): Passage: In 1870, concerned at the dominance of German music and the lack of opportunity for young French composers to have their works played, Saint-Saëns and Romain Bussine, professor of singing at the Conservatoire, discussed the founding of a society to promote new French music. Before they could take the proposal further, the Franco-Prussian War broke out. Saint-Saëns served in the National Guard during the war. During the brief but bloody Paris Commune that followed, his superior at the Madeleine, the Abbé Deguerry, was murdered by rebels; Saint-Saëns was fortunate to escape to temporary exile in England where he arrived in May 1871. With the help of George Grove and others he supported himself while there, giving recitals. Returning to Paris in the same year, he found that anti-German sentiments had considerably enhanced support for the idea of a pro-French musical society. The Société Nationale de Musique, with its motto, "Ars Gallica", had been established in February 1871, with Bussine as president, Saint-Saëns as vice-president and Henri Duparc, Fauré, Franck and Jules Massenet among its founder-members.
As an admirer of Liszt's innovative symphonic poems, Saint-Saëns enthusiastically adopted the form; his first "poème symphonique" was Le Rouet d'Omphale (1871), premiered at a concert of the Sociéte Nationale in January 1872. In the same year, after more than a decade of intermittent work on operatic scores, Saint-Saëns finally had one of his operas staged. La princesse jaune ("The Yellow Princess"), a one-act, light romantic piece, was given at the Opéra-Comique, Paris in June. It ran for five performances.Throughout the 1860s and early 1870s, Saint-Saëns had continued to live a bachelor existence, sharing a large fourth-floor flat in the Rue du Faubourg Saint-Honoré with his mother. In 1875, he surprised many by marrying. The groom was approaching forty and his bride was nineteen; she was Marie-Laure Truffot, the sister of one of the composer's pupils. The marriage was not a success. In the words of the biographer Sabina Teller Ratner, "Saint-Saëns's mother disapproved, and her son was difficult to live with". Saint-Saëns and his wife moved to the Rue Monsieur-le-Prince, in the Latin Quarter; his mother moved with them. The couple had two sons, both of whom died in infancy. In 1878, the elder, André, aged two, fell from a window of the flat and was killed; the younger, Jean-François, died of pneumonia six weeks later, aged six months. Saint-Saëns and Marie-Laure continued to live together for three years, but he blamed her for André's accident; the double blow of their loss effectively destroyed the marriage. 
Question: What was the full name of the sister of one of Saint-Saëns' pupils?
Output (English): Marie-Laure Truffot.