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.
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.
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.
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.
Catherine I, Latin Empress
Catherine I, also Catherine of Courtenay (25 November 1274 – 11 October 1307), was the recognised Latin Empress of Constantinople from 1283 to 1307, although she lived in exile and only held authority over Crusader States in Greece.
In 1301, she became the second wife of Charles of Valois, by whom she had one son and three daughters; the eldest of these, Catherine II of Valois, Princess of Achaea succeeded her as titular empress.
Alice of Courtenay
Alice of Courtenay, Countess of Angoulême( 1160 – 12 February 1218) was a French noblewoman of the House of Courtenay.
Her father was Peter I of Courtenay and her brother was Peter II of Courtenay, Latin Emperor of Constantinople.
Alice married twice; by her second husband, Aymer Taillefer, Count of Angoulême, she was the mother of Isabella of Angoulême, who was Queen consort of England, as the wife of King John.
She is also known as Alix de Courtenay.
Agnes of Courtenay
Agnes of Courtenay( c. 1136 – c. 1184) was Queen of Jerusalem as the wife of King Amalric I of Jerusalem.
She was the daughter of Joscelin II of Courtenay by his wife Beatrice of Saone, and the mother of King Baldwin IV and Queen Sibylla of Jerusalem.
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.
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.

Question: Who is the mother-in-law of Catherine I, Latin Empress?
Answer: Isabella of Aragon