question: What is the date of birth of Hedvig Elizabeth Von Biron's mother?
context: [["Terence Robinson", ["Terence D. Robinson( date of birth and death unknown) was a male wrestler who competed for England."]], ["Theodred II (Bishop of Elmham)", ["Theodred II was a medieval Bishop of Elmham.", "The date of Theodred's consecration unknown, but the date of his death was sometime between 995 and 997."]], ["Yelizaveta Palmenbach", ["Yelizaveta Palmenbach( 1761\u20131832) was an Imperial Russian pedagogue, the principal of the Smolny Institute in Saint Petersburg from 1797 \u2013 1802.", "She was the daughter of Baron Aleksandr Ivanovich Cherkasov and Hedvig Elizabeth von Biron( 1727 \u2013 1797), sister of Peter von Biron.", "She was educated at the Smolny Institute, where she graduated in 1779, and was a lady- in- waiting prior to her marriage to Yevstafi Palmenbach in 1793, with whom she had three daughters.", "In 1796, she became assistant director of Sophie Lafont, and replaced her as principal in 1797.", "She was also the governess of the Grand Duchesses."]], ["Benigna Gottliebe von Trotta genannt Treyden", ["Benigna Gottliebe von Trotta genannt Treyden( 15 October 1703 \u2013 5 November 1782), was a Duchess consort of Courland.", "She married the Duke of Courland, Ernst Johann von Biron, on 25 February 1723."]], ["Brian Saunders (weightlifter)", ["Brian Saunders( date of birth and death unknown) was a male weightlifter who competed for England."]], ["Ernst Johann von Biron", ["Ernst Johann von Biron) was a Duke of Courland and Semigallia( 1737) and briefly regent of the Russian Empire in 1740."]], ["Les Richards", ["Les Richards( date of birth unknown) was an Australian rules footballer who played with North Melbourne in the Victorian Football League( VFL)."]], ["Etan Boritzer", ["Etan Boritzer( born 1950) is an American writer of children \u2019s literature who is best known for his book\" What is God?\" first published in 1989.", "His best selling\" What is?\" illustrated children's book series on character education and difficult subjects for children is a popular teaching guide for parents, teachers and child- life professionals.", "Boritzer gained national critical acclaim after\" What is God?\" was published in 1989 although the book has caused controversy from religious fundamentalists for its universalist views.", "The other current books in the\" What is?\" series include", "What is Love?,", "What is Death?,", "What is Beautiful?,", "What is Funny?,", "What is Right?,", "What is Peace?,", "What is Money?,", "What is Dreaming?,", "What is a Friend?,", "What is True?,", "What is a Family?,", "What is a Feeling?\"", "The series is now also translated into 15 languages.", "Boritzer was first published in 1963 at the age of 13 when he wrote an essay in his English class at Wade Junior High School in the Bronx, New York on the assassination of John F. Kennedy.", "His essay was included in a special anthology by New York City public school children compiled and published by the New York City Department of Education.", "Boritzer now lives in Venice, California and maintains his publishing office there also.", "He has helped numerous other authors to get published through\" How to Get Your Book Published!\" programs.", "Boritzer is also a yoga teacher who teaches regular classes locally and guest- teaches nationally.", "He is also recognized nationally as an erudite speaker on\" The Teachings of the Buddha.\""]], ["Annette Bjelkevik", ["Annette Bjelkevik( born 12 May 1978) is a Norwegian speed skater.", "She was born in Arendal and is the sister of Hedvig Bjelkevik.", "She competed in the 1,500 m, 3,000 m and team pursuit at the 2006 Winter Olympics in Turin."]], ["Hedvig Elizabeth von Biron", ["Hedvig Elizabeth von Biron of Courland( 1727\u20131797), was a princess of Courland and a Russian courtier, daughter of the Duke of Courland, Ernst Johann von Biron, and Benigna Gottlieb von Trotha gt Treyden, and the sister of Peter von Biron.", "She was the Ober- Hofmeisterin of the Empress Elizabeth of Russia and an influential person at the Russian court."]]]
supporting_facts: [["Hedvig Elizabeth von Biron", 0], ["Benigna Gottliebe von Trotta genannt Treyden", 0]]
evidences: [["Hedvig Elizabeth von Biron", "mother", "Benigna Gottlieb von Trotha gt Treyden"], ["Benigna Gottliebe von Trotta genannt Treyden", "date of birth", "15 October 1703"]]
answer: 15 October 1703