Gottlieb Muffat (April 1690 – 9 December 1770), son of Georg Muffat, served as "Hofscholar" under Johann Fux in Vienna from 1711 and was appointed to the position of third court organist at the "Hofkapelle" in 1717.
 He acquired additional duties over time including the instruction of members of the Imperial family, among them the future Empress Maria Theresa.
 He was promoted to second organist in 1729 and first organist upon the accession of Maria Theresa to the throne in 1741.
 He retired from official duties at the court in 1763.
Orfeo ed Euridice (French version: Orphée et Eurydice ; English: "Orpheus and Eurydice") is an opera composed by Christoph Willibald Gluck based on the myth of Orpheus, set to a libretto by Ranieri de' Calzabigi.
 It belongs to the genre of the "azione teatrale", meaning an opera on a mythological subject with choruses and dancing.
 The piece was first performed at the Burgtheater in Vienna on 5 October 1762 in the presence of Empress Maria Theresa.
 "Orfeo ed Euridice" is the first of Gluck's "reform" operas, in which he attempted to replace the abstruse plots and overly complex music of "opera seria" with a "noble simplicity" in both the music and the drama.
Maria Theresa (German: Maria Theresia) is a 1951 Austrian historical drama film directed by  Emil E. Reinert and starring  Paula Wessely, Fred Liewehr and Marianne Schönauer.
 It portrays the life of the eighteenth century Habsburg Empress Maria Theresa.
The Maria Theresa thaler (MTT) is a silver bullion coin that has been used in world trade continuously since they were first minted in 1741, at that time using the then Reichsthaler standard of 9 thalers to the Vienna mark.
 In 1750 the thaler was debased to 10 thalers to the Vienna Mark (a weight approximating half a pound of fine silver).
 The following year the new standard was effectively adopted across the German-speaking world when that standard was accepted formally in the Bavarian monetary convention.
 It is owing to the date of the Bavarian Monetary convention that many writers erroneously state that the Maria Theresa Thaler was first struck in 1751.
 It was named after Empress Maria Theresa, who ruled Austria, Hungary, and Bohemia from 1740 to 1780.
 The word "thaler" gave rise to "daalder" and "daler", which became "dollar" in English.
The Mozart family grand tour was a journey through western Europe, undertaken by Leopold Mozart, his wife Anna Maria, and their musically gifted children Maria Anna (Nannerl) and Wolfgang Amadeus from 1763 to 1766.
 At the start of the tour the children were aged eleven and seven respectively.
 Their extraordinary skills had been demonstrated during a visit to Vienna in 1762, when they had played before the Empress Maria Theresa at the Imperial Court.
 Sensing the social and pecuniary opportunities that might accrue from a prolonged trip embracing the capitals and main cultural centres of Europe, Leopold obtained an extended leave of absence from his post as deputy Kapellmeister to the Prince-Archbishop of Salzburg.
 Throughout the subsequent tour, the children's "Wunderkind" status was confirmed as their precocious performances consistently amazed and gratified their audiences.
The Imperial and Royal Decoration of Elizabeth and Theresa (in German: "Elisabeth-Theresien-Orden") was a decoration of the Austro-Hungarian Empire, created in 1750 by Empress Consort Elizabeth Christine in her testament.
 It was later revised in 1771 by her daughter Empress Maria Theresa I, Holy Roman Empress, as the "Elizabetho-Theresian Military Foundation" ("Elisabeth-Theresianische Militärstiftung") .
Adam František Kollár de Keresztén (German: "Adam Franz Kollar von Keresztén" , Hungarian: "kereszténi Kollár Ádám Ferenc" ; 1718–1783) was a Slovak jurist, Imperial-Royal Court Councilor and Chief Imperial-Royal Librarian, a member of Natio Hungarica in the Kingdom of Hungary, a historian, ethnologist, an influential advocate of Empress Maria Theresa's Enlightened and centralist policies.
 His advancement of Maria Theresa's status in the Kingdom of Hungary as its apostolic ruler in 1772 was used as an argument in support of the subsequent Habsburg annexations of Galicia and Dalmatia.
 Kollár is also credited with coining the term "ethnology" and providing its first definition in 1783.
 Some authors see him as one of the earliest pro-Slovak, pro-Slavic, and pan-Slavic activists in the Habsburg Monarchy.
Maria Theresa of Austria (21 March 1801 – 12 January 1855) was born an Archduchess of Austria and Princess of Tuscany.
 She was a daughter of Ferdinand III, Grand Duke of Tuscany, and Luisa of Naples and Sicily.
 She was named after her double great grandmother Empress Maria Theresa.
 In 1817, she married Charles Albert of Sardinia and subsequently became the Queen of Sardinia upon her husband's accession to the throne in 1831.
Maria Anna Walburga Ignatia Mozart (30 July 1751 – 29 October 1829), called Marianne and nicknamed "Nannerl", was a musician, the older sister of Wolfgang Amadeus Mozart and daughter of Leopold and Anna Maria Mozart.
Maria Theresa or Maria Theresia most often refers to Empress Maria Theresa (1717-1780), Queen of Hungary and Bohemia, Archduchess of Austria and ruler of the rest of the Habsburg Empire (1740-1780).

Question: What is the full name of the eldest sibling who performed for the Empress Maria Theresa at the Imperial Court during a visit to Vienna in 1762?
Answer: Maria Anna Walburga Ignatia Mozart