Question: When was the older sister of Princess Benedikte of Denmark born?

Context articles: Margrethe II of Denmark
Princess Alexandra of Sayn-Wittgenstein-Berleburg
Princess Benedikte of Denmark
Princess Nathalie of Sayn-Wittgenstein-Berleburg
Gustav, 7th Prince of Sayn-Wittgenstein-Berleburg
Princess Tatiana of Sayn-Wittgenstein-Berleburg
Princess Astrid, Mrs. Ferner
Jonny Briggs
Margareta Fouché
Princess Takata

Margrethe II (Danish: "Margrethe 2."
 , ] ; Faroese: "Margreta 2."
 ; Greenlandic: "Margrethe II" ; full name: "Margrethe Alexandrine Þórhildur Ingrid"; born 16 April 1940) is the Queen of Denmark.
 She is also the supreme authority of the Church of Denmark and Commander-in-Chief of the Danish Defence.
 Born into the House of Glücksburg, a royal house with origins in Northern Germany, she was the eldest child of Frederick IX of Denmark and Ingrid of Sweden.
 She succeeded her father upon his death on 14 January 1972, having had become heir presumptive to her father in 1953, when a constitutional amendment allowed women to inherit the throne.
 On her accession, Margrethe became the first female monarch of Denmark since Margaret I, ruler of the Scandinavian kingdoms in 1375–1412 during the Kalmar Union.
 In 1967, she married Henri de Laborde de Monpezat, with whom she has two sons: Crown Prince Frederik (born 1968) and Prince Joachim (born 1969).
 She has been on the Danish throne for 45 years, becoming the second-longest-reigning Danish monarch after her ancestor Christian IV.
Princess Alexandra of Sayn-Wittgenstein-Berleburg, Countess von Pfeil und Klein-Ellguth (Alexandra Rosemarie Ingrid Benedikte; born 20 November 1970 in Copenhagen, Denmark), is the first daughter and second of three children of Prince Richard of Sayn-Wittgenstein-Berleburg and Princess Benedikte of Denmark).
Princess Benedikte of Denmark, Princess of Sayn-Wittgenstein-Berleburg {'1': ", '2': ", '3': 'RE, SKmd, D.Ht.
', '4': "} (Benedikte Astrid Ingeborg Ingrid, born 29 April 1944) is the second daughter of King Frederick IX of Denmark and Ingrid of Sweden.
 She is the younger sister of the reigning Queen of Denmark, Margrethe II, and the older sister of Queen Anne-Marie of Greece.
Princess Nathalie of Sayn-Wittgenstein-Berleburg (Nathalie Xenia Margrethe Benedikte; born 2 May 1975, in Copenhagen, Denmark) is the youngest daughter of Prince Richard of Sayn-Wittgenstein-Berleburg and Princess Benedikte of Denmark and niece of Queen Margrethe II of Denmark and Queen Anne-Marie of Greece.
Gustav, 7th Prince of Sayn-Wittgenstein-Berleburg (Gustav Frederik Philip Richard; born 12 January 1969 in Frankfurt-am-Main, Germany), is the eldest child and only son of Princess Benedikte of Denmark and Richard, 6th Prince of Sayn-Wittgenstein-Berleburg.
Princess Tatiana of Sayn-Wittgenstein-Berleburg (Tatiana Louise Ursula Therese Elsa; born 31 July 1940) is the fourth child and second daughter of Gustav Albrecht, 5th Prince of Sayn-Wittgenstein-Berleburg, and his wife, Margareta Fouché d'Otrante, and younger sister of Prince Richard of Sayn-Wittgenstein-Berleburg, the husband of Princess Benedikte of Denmark.
 Tatjana is the former wife of the late Moritz, Landgrave of Hesse, from 1980 head of the House of Hesse.
 Their marriage took place in the summer of 1964 in Gießen.
 They divorced in 1974.
Princess Astrid, Mrs. Ferner (Astrid Maud Ingeborg; born 12 February 1932 in Oslo, Norway) is the second daughter of King Olav V of Norway and his wife, Princess Märtha of Sweden.
 She is the older sister of King Harald V of Norway and younger sister of the late Princess Ragnhild.
Jonny Briggs is a Children's BBC kitchen sink realism television programme first broadcast in 1985.
 It revolves around the exploits of a young boy, the eponymous hero (played by Richard Holian), his pet dog, Razzle, and his eccentric family members: Mam (Jane Lowe) and Dad (Leslie Schofield), older sister Rita (Sue Devaney) and older brothers Albert (Tommy Robinson) and Humph (Humphrey) (Jeremy Austin).
 Another older sister, Marilyn, is mentioned but never seen.
 The stories often centre on Jonny's school life, where he and his best friend Pam are constantly in battle with the dreadful twins Ginny and Josie.
Margareta Fouché d'Otrante, Princess of Sayn-Wittgenstein-Berleburg (28 March 1909 – 25 August 2005) was the wife of Gustav Albrecht, 5th Prince of Sayn-Wittgenstein-Berleburg, and mother of Richard, 6th Prince of Sayn-Wittgenstein-Berleburg, who married Princess Benedikte of Denmark.
Princess Takata (田形皇女 , 674–728) was a Japanese princess during the Asuka period and Nara period of Japanese history.
 She was a daughter of Emperor Tenmu and Lady Ōnu whose father was Soga no Akaye.
 Prince Hozumi was her older brother, and Princess Ki was her older sister.
 She was a "Saiō".