Princess Wilhelmina Caroline of Denmark
Princess Wilhelmina "Caroline" of Denmark and Norway  (10 July 1747 in Christiansborg Palace, Copenhagen – 14 January 1820 in Kassel), was the Landgravine consort of Hesse-Kassel and later the Electress of Hesse-Kassel by marriage to William I, Elector of Hesse.
Marian Shields Robinson
Marian Lois Robinson( née Shields; born July 29, 1937) is the mother of Michelle Obama, former First Lady of the United States, and Craig Robinson, a basketball executive, and the mother- in- law of former U.S. President Barack Obama.
Maria Thins
Maria Thins( c. 1593 – 27 December 1680) was the mother- in- law of Johannes Vermeer and a member of the Gouda Thins family.
Eldon Howard
Eldon Howard was a British screenwriter.
She was the mother- in- law of Edward J. Danziger and wrote a number of the screenplays for films by his company Danziger Productions.
Marie Friederike of Hesse-Kassel
Marie Frederike of Hesse- Kassel( 14 September 1768, Hanau – 17 April 1839, Hanau) was a German noblewoman and by marriage Princess and later Duchess of Anhalt- Bernburg.
She was a daughter of William I, Elector of Hesse, and his wife, Princess Wilhelmina Caroline of Denmark.
Princess Karoline Amalie of Hesse-Kassel
Karoline Amalie of Hesse- Kassel( 11 July 1771, Hanau – 22 February 1848, Gotha), was a German princess and member of the House of Hesse- Kassel by birth, and Duchess of Saxe- Gotha- Altenburg by marriage.
She was the second daughter of Landgrave( later Prince) William I of Hesse by Princess Wilhelmina Caroline of Denmark and Norway, daughter of King Frederick V.
Princess Caroline of Great Britain
Princess Caroline of Great Britain (Caroline Elizabeth; 10 June 1713 – 28 December 1757) was the fourth child and third daughter of King George II of Great Britain and his wife Caroline of Ansbach.
Priscilla Pointer
Priscilla Marie Pointer( born May 18, 1924) is an American stage, film and television character actress.
She began her career in the theater, including productions on Broadway.
Later, Pointer moved to Hollywood to act in films and on television.
She is the mother of Amy Irving, therefore making her the former mother- in- law of filmmakers Steven Spielberg and Bruno Barreto and the mother- in- law of documentary filmmaker Kenneth Bowser, Jr.
William I, Elector of Hesse
William I, Elector of Hesse (3 June 1743 – 27 February 1821) was the eldest surviving son of Frederick II, Landgrave of Hesse-Kassel (or Hesse-Cassel) and Princess Mary of Great Britain, the daughter of George II.
Ellen Marsvin
Ellen Marsvin (1 February 1572 – 11 November 1649) was a Danish noble, landowner and county administrator.
She was the mother-in-law of King Christian IV of Denmark, the mother of Kirsten Munk (1598–1658) and grandmother of Leonora Christina Ulfeldt (1621–1698).

Question: Who is Princess Wilhelmina Caroline Of Denmark's mother-in-law?
Answer: Princess Mary of Great Britain