Gian Galeazzo Visconti
Gian Galeazzo Visconti (16 October 1351 – 3 September 1402), son of Galeazzo II Visconti and Bianca of Savoy, was the first Duke of Milan (1395) and ruled the late-medieval city just before the dawn of the Renaissance.
He was the founding patron of the Certosa di Pavia, completing the Visconti Castle at Pavia begun by his father and furthering work on the Duomo of Milan.
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.
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.
Isabella, Countess of Gloucester
Isabella, Countess of Gloucester( c. 1173 – 14 October 1217), was an English noblewoman who was married to King John prior to his accession.
Margaret, Countess of Vertus
Margaret, Countess of Vertus( French:" Marguerite d' Orléans"; 4 December 1406 – 1466), was a French vassal, Countess of Vertus and Etampes 1420 – 1466.
She was the daughter of Louis I, Duke of Orléans, and Valentina Visconti.
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.
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.
William Comyn of Kirkintilloch
William Comyn of Kirkintilloch( died 1291) was a 13th- century Scottish nobleman.
He was a son of John Comyn, Lord of Badenoch( died c. 1275) and Alicia de Ros. William was married to Isabella Russell, daughter of Isabella, Countess of Menteith and John Russell.
Petitions were placed to King Edward I of England and King Alexander III of Scotland claiming the Earldom of Mentieth, in the right of Isabella, his wife and in 1285 half the lands of the Earldom of Mentieth were granted to William and Isabella.
The title of the Earl of Mentieth was kept by Walter Bailloch, jure uxoris by his wife Mary, sister of Isabella, Countess of Menteith.
William died in 1291, without issue by his own wife.
Isabella, Countess of Vertus
Isabella of France (1 October 1348 – 11 September 1373) was a French princess and member of the House of Valois, as well as the wife of Gian Galeazzo Visconti, who after her death became Duke of Milan.
Born in Bois de Vincennes, Isabella was the youngest daughter of King John II of France by his first wife, Bonne of Bohemia.
Her maternal uncle Count Amadeus VI of Savoy arranged her marriage with Gian Galeazzo Visconti.
As her dowry, Isabella received the county of Sommières, exchanged later for the county of Vertus.
On 8 October 1360, Isabella and Gian Galeazzo were married in Milan, and six months later, in April 1361, she was declared sovereign Countess of Vertus.
The couple had four children:
Isabella died in childbirth in Pavia in 1373.
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 Isabella, Countess Of Vertus's mother-in-law?
Answer: Bianca of Savoy