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.
Baroness Gösta von dem Bussche-Haddenhausen
Baroness Gösta von dem Bussche- Haddenhausen( 26 January 1902 – 13 June 1996) was the mother of Prince Claus of the Netherlands, who was the Prince Consort of Queen Beatrix of the Netherlands, thus making her the mother- in- law of the former Dutch Queen.
She is also the paternal grandmother of King Willem- Alexander of the Netherlands, who is the current Dutch King.
Vera Miletić
Vera Miletić (Serbian Cyrillic: Вера Милетић; 8 March 1920 – 7 September 1944) was a Serbian student and soldier.
She was notable for being the mother of Mira Marković, posthumously making her the mother-in-law of Serbian president Slobodan Milošević.
Ebba Eriksdotter Vasa
Ebba Eriksdotter Vasa (circa 1491 – 21 November 1549) was a Swedish noblewoman.
She was the mother of Queen Margaret Leijonhufvud and the second cousin and mother-in-law of King Gustav Vasa.
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.
Cornelia (mother of the Gracchi)
Cornelia( c. 190s – c. 115 BC) was the second daughter of Publius Cornelius Scipio Africanus, the hero of the Second Punic War, and Aemilia Paulla.
She is remembered as a prototypical example of a virtuous Roman woman.
She was the mother of the Gracchi brothers, and the mother- in- law of Scipio Aemilianus.
Ferdinand VI of Spain
Ferdinand VI of Spain (23 September 1713 – 10 August 1759), called the Learned ("el Prudente") and the Just ("el Justo"), King of Spain from 9 July 1746 until his death in 1759, was the third ruler of the Spanish Bourbon dynasty.
He was the fourth son of the previous monarch Philip V and his first wife Maria Luisa of Savoy.
Barbara of Portugal
Barbara of Portugal (Maria Madalena Bárbara Xavier Leonor Teresa Antónia Josefa; 4 December 1711 – 27 August 1758) was an Infanta of Portugal, and a Queen of Spain by marriage to Ferdinand VI of Spain.
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.
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.

Question: Who is the mother-in-law of Barbara Of Portugal?
Answer: Maria Luisa of Savoy