Question: Princess Stephanie of Windisch-Graetz, was the daughter of Prince Otto Weriand of Windisch-Graetz, and was the only child of Rudolf, Crown Prince of Austria and Princess Stéphanie of Belgium?
Context: Muqrin bin Abdulaziz Al Saud (Arabic: مقرن بن عبدالعزيز آل سعود‎ ‎ ; born 15 September 1945) is a member of House of Saud who served as Crown Prince of Saudi Arabia from January to April 2015.  He was Director General of Al Mukhabarat Al A'amah (Saudi Intelligence Agency) from 2005 to 2012.  In July 2012, Muqrin was appointed King Abdullah's Advisor and Special Envoy with the rank of minister.  On 1 February 2013, King Abdullah named him as Second Deputy Prime Minister, being the fifth Saudi royal to hold this position.  This post was previously held by King Fahd, King Abdullah, Crown Prince Sultan, and Crown Prince Nayef.  On 27 March 2014, he was named Deputy Crown Prince making him second in the line of succession behind his brother Salman bin Abdulaziz Al Saud.  On 23 January 2015, upon King Abdullah's death and the accession of King Salman, Muqrin became Crown Prince and First Deputy Prime Minister.  On 29 April 2015, King Salman replaced Prince Muqrin with Prince Muhammad bin Nayef as Crown Prince. Stéphanie Windisch-Graetz (born 17 July 1939) is the daughter of Prince Franz Joseph zu Windisch-Graetz and granddaughter of Archduchess Elisabeth Marie of Austria.  Archduchess Elisabeth was the daughter of Rudolf, Crown Prince of Austria and granddaughter of Emperor Franz Joseph I of Austria. Princess Stéphanie of Belgium (21 May 1864 – 23 August 1945) was a Belgian princess by birth and became Crown Princess of Austria through her marriage to the heir-apparent of the Habsburg dynasty, Archduke Rudolf.  She was famously widowed in 1889 when Rudolf and his mistress, Mary Vetsera, were found dead in an apparent murder-suicide pact at the Imperial hunting lodge at Mayerling in the Vienna Woods. Archduke Felix of Austria (given names: "Felix Friedrich August Maria vom Siege Franz Joseph Peter Karl Anton Robert Otto Pius Michael Benedikt Sebastian Ignatius Marcus d'Aviano"; 31 May 1916 – 6 September 2011) was the last surviving child of the last Austrian Emperor Charles I and a member of the Habsburg.  He was a younger brother of former Crown Prince Otto of Austria, who predeceased Felix by two months. The 1895 Wimbledon Championships took place on the outdoor grass courts at the All England Lawn Tennis Club in Wimbledon, London, United Kingdom.  The tournament ran from 8 July until 15 July.  It was the 19th staging of the Wimbledon Championships, and the first Grand Slam tennis event of 1895.  There were 18 competitors for the men's singles title.  The meeting recorded its only loss, of 33 pounds, despite its first visit from royalty, Princess Stephanie of Belgium, Crown Princess of Austria. Princess Stéphanie of Monaco, Countess of Polignac (Stéphanie Marie Elisabeth Grimaldi; born 1 February 1965) is the youngest child of Rainier III, Prince of Monaco, and American actress princess Grace of Monaco, and the sister of Albert II, Prince of Monaco, and Caroline, Princess of Hanover.  Currently 11th in the line of succession to the Monegasque throne, she has been a singer, swimwear designer and fashion model. Sophie, Princess of Windisch-Graetz (born Sophie Franziska Maria Germaine of Habsburg-Lorraine, Archduchess of Austria, 19 January 1959) is a member by birth of the House of Habsburg-Lorraine, and by marriage of the Austrian House of Windisch-Graetz. Archduchess Elisabeth Marie of Austria (Elisabeth Maria Henriette Stephanie Gisela; 2 September 1883 – 16 March 1963) was the only child of Rudolf, Crown Prince of Austria and Princess Stéphanie of Belgium, and a granddaughter of Emperor Franz Joseph I of Austria and King Leopold II of the Belgians.  She was known to the family as "Erzsi", a diminutive of her name in Hungarian.  Later nicknamed "The Red Archduchess", she was famous for becoming a socialist and a member of the Austrian Social Democratic Party. Caroline, Princess of Hanover (Caroline Louise Marguerite Grimaldi; born 23 January 1957), is the eldest child of Rainier III, Prince of Monaco, and American actress Grace Kelly.  She is the elder sister of Prince Albert II and Princess Stéphanie.  Until the births of her niece and nephew Princess Gabriella and Prince Jacques of Monaco in December 2014 she had been heir presumptive to the throne of Monaco since 2005, a position which she previously held from 1957 to 1958. Princess Stéphanie of Windisch-Graetz (April 4, 1909 in Ploskovice, Bohemia – May 29, 2005 in Uccle, Belgium) was the daughter of Prince Otto Weriand of Windisch-Graetz (1873–1952) and Archduchess Elisabeth Marie of Austria (1883–1963), only child of Crown Prince Rudolf of Austria and Princess Stéphanie of Belgium.  She was the great-grandchild of Emperor Franz-Joseph and Empress Elisabeth ('Sissi') of Austria.  She was also the great-grandchild of King Leopold II of Belgium.
Answer: Archduchess Elisabeth Marie of Austria