Question: When did Princess Stéphanie Of Monaco's mother die?

Context paragraphs:
title: Daniel Ducruet
paragraph_text: Daniel Ducruet( born 27 November 1964) is a former husband of Princess Stéphanie of Monaco, to whom he was married in 1995 and divorced from a year later in 1996. Two of his children, Louis and Pauline, are 15th and 16th in the line of succession to the Monegasque throne.
title: Elisabeth-Anne de Massy
paragraph_text: Baroness Elisabeth-Anne de Massy Noghès (born 13 January 1947) is the daughter of Princess Antoinette of Monaco and Alexandre-Athenase Noghès. She is a first cousin of the reigning Prince Albert II and niece of Rainier III. She is the godmother of Princess Stéphanie of Monaco. Although Elisabeth-Anne was born out of wedlock, her parents married in 1951, thus legitimizing her, and placing her in line to the throne. Baroness Elisabeth Anne can represent the Sovereign Prince of Monaco at official events.
title: Grace Kelly
paragraph_text: Grace Patricia Kelly (November 12, 1929September 14, 1982) was an American film actress who, after starring in several significant films in the early- to mid-1950s, became Princess of Monaco by marrying Prince Rainier III in April 1956. After embarking on an acting career in 1950 when she was 20, Kelly appeared in New York City theatrical productions and more than 40 episodes of live drama productions broadcast during the early 1950s Golden Age of Television. From 1952 to 1956 she starred in several critically and commercially successful films, usually opposite male romantic leads 25 to 30 years older than her. In October 1953, she gained stardom from her performance in director John Ford's African-filmed adventure-romance "Mogambo", starring Clark Gable and Ava Gardner, which won her a Golden Globe Award and an Academy Award nomination for Best Supporting Actress. In 1954 she won the Academy Award for Best Actress for her deglamorized performance in the drama "The Country Girl" with Bing Crosby. Other noteworthy films in which she starred include the western "High Noon" (1952), with Gary Cooper; the romance-comedy musical "High Society" (1956), with Bing Crosby and Frank Sinatra; and three Alfred Hitchcock suspense thrillers in rapid succession: "Dial M for Murder" (1954), with Ray Milland; "Rear Window" (1954), with James Stewart; and "To Catch a Thief" (1955), with Cary Grant. Kelly retired from acting at the age of 26 to marry Rainier, and began her duties as Princess of Monaco. It is well known that Hitchcock was hoping she would appear in more of his films which required an "icy blonde" lead actress, but he was unable to coax her out of retirement. Kelly and Rainier had three children: Princess Caroline, Prince Albert, and Princess Stéphanie. Kelly retained her link to America by her dual U.S. and Monégasque citizenship. Princess Grace died at Monaco Hospital on September 14, 1982, succumbing to injuries sustained in a traffic collision the previous day. At the time of her death she was 52 years old. She is listed 13th among the American Film Institute's 25 Greatest Female Stars of Classical Hollywood Cinema.
title: Princess Charlotte, Duchess of Valentinois
paragraph_text: Princess Charlotte of Monaco, Duchess of Valentinois( Charlotte Louise Juliette Grimaldi; 30 September 1898 – 15 November 1977), was the daughter of Louis II, Prince of Monaco, and the mother of Rainier III, Prince of Monaco. From 1922 until 1944, she was the Hereditary Princess of Monaco, heir presumptive to the throne.
title: Claudine, Lady of Monaco
paragraph_text: Claudine or Claudia( – 19 November 1515) was Lady regnant of Monaco between 1457 and 1458, and the Lady consort of Monaco by marriage to Lord Lambert of Monaco.
title: Ippolita Trivulzio
paragraph_text: Ippolita Trivulzio( 1600 – 20 June 1638) was the Princess of Monaco by marriage to Honoré II of Monaco, and was the first Monegasque consort to bear the title of" Princess".
title: Princess Stéphanie of Monaco
paragraph_text: 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 the American actress Grace Kelly. She is the younger sister of Albert II, Prince of Monaco, and Caroline, Princess of Hanover. Currently 14th in the line of succession to the Monegasque throne, she has been a singer, swimwear designer and fashion model.
title: Pauline Ducruet
paragraph_text: Pauline Grace Maguy Ducruet( born 4 May 1994) is the elder daughter of Princess Stéphanie of Monaco. Her maternal grandparents were Rainier III, Prince of Monaco, and American actress Grace Kelly. She is the niece of Prince Albert II. Ducruet is currently 16th in the line of succession to the Monegasque throne.
title: Louis Ducruet
paragraph_text: Louis Robert Paul Ducruet( born 26 November 1992) is the son of Princess Stéphanie of Monaco and Daniel Ducruet. Although he holds no title, he is a grandson of Rainier III, Prince of Monaco, and American actress Grace Kelly. As nephew of Prince Albert II, he is currently 15th in the line of succession to the Monegasque throne.
title: Princess Stephanie of Windisch-Graetz
paragraph_text: 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. Her full name was" Stéphanie Eleonore Maria Elisabeth Kamilla Philomena Veronika zu Windisch- Grätz" in German, and" Stéphanie Éléonore Marie Élisabeth Camille Philomène Véronique de Windisch- Grätz" in French. She may have been named after her maternal grandmother, Princess Stéphanie of Belgium. Her nickname in the family was Fée.

Reasoning steps:
Princess Stéphanie of Monaco mother Grace Kelly
Grace Kelly date of death September 14, 1982

Answer: spans: September 14, 1982