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.
Blanche of Valois
Blanche of Valois (baptised "Marguerite"; 1317–1348) was a Queen consort of Germany and Bohemia by her marriage to King and later Holy Roman Emperor Charles IV.
She was the youngest daughter of Charles of Valois and his third wife Mahaut of Châtillon.
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.
Blanche of Bourbon
Blanche of Bourbon( 1339 – 1361) was Queen of Castile as the wife of King Peter.
She was one of the daughters of Peter I, Duke of Bourbon and Isabella of Valois.
Joan of Valois, Countess of Hainaut
Joan of Valois( c. 1294 – 7 March 1342) was a Countess consort of Hainaut, Holland, and Zeeland.
She was the second eldest daughter of the French prince Charles, Count of Valois, and his first wife, Margaret, Countess of Anjou.
As the sister of King Philip VI of France and the mother- in- law of Edward III, she was ideally placed to act as mediator between them.
Charles, Count of Valois
Charles of Valois( 12 March 1270 – 16 December 1325), the third son of Philip III of France and Isabella of Aragon, was a member of the House of Capet and founder of the House of Valois, whose rule over France would start in 1328.
Charles ruled several principalities.
He held in appanage the counties of Valois, Alençon and Perche.
Through his marriage to Margaret of Anjou, he became Count of Anjou and Maine.
Through his marriage to Catherine I, titular empress of the Latin Empire, he was titular Latin Emperor of Constantinople from 1301 – 1307, although he ruled from exile and only had authority over Crusader States in Greece.
The grandson of Louis IX of France, Charles of Valois was a son, brother, brother- in- law and son-in- law of kings or queens( of France, Navarre, England and Naples).
His descendants, the House of Valois, would become the royal house of France three years after his death, beginning with his son Philip VI of France.
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.
Charles IV, Holy Roman Emperor
Charles IV (14 May 1316 – 29 November 1378), born Wenceslaus, was the first King of Bohemia to become Holy Roman Emperor.
He was a member of the House of Luxembourg from his father's side and the Czech House of Přemyslid from his mother's side; he emphasized the latter due to his lifelong affinity for the Czech side of his inheritance, and also because his direct ancestors in the Přemyslid line included two saints.
He was the eldest son and heir of King John of Bohemia, who died at the Battle of Crécy on 26 August 1346.
His mother, Elizabeth of Bohemia, was the sister of King Wenceslas III, the last of the male Přemyslid rulers of Bohemia.
Charles inherited the County of Luxembourg from his father and was elected king of the Kingdom of Bohemia.
On 2 September 1347, Charles was crowned King of Bohemia.
On 11 July 1346, the prince-electors chose him as King of the Romans ("rex Romanorum") in opposition to Emperor Louis IV.
Charles was crowned on 26 November 1346 in Bonn.
After his opponent died, he was re-elected in 1349 and crowned King of the Romans.
In 1355, he was crowned King of Italy and Holy Roman Emperor.
With his coronation as King of Burgundy in 1365, he became the personal ruler of all the kingdoms of the Holy Roman Empire.
Marie of Valois, Duchess of Calabria
Marie of Valois( 1309 – 23 October 1331), was the eldest daughter of Charles of Valois by his third wife Mahaut of Châtillon.
She was a member of the House of Valois.
One of her five children was Queen Joanna I of Naples.

Question: Who is the mother-in-law of Blanche Of Valois?
Answer: Elizabeth of Bohemia