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.
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.
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.
Ursula Pole, Baroness Stafford
Ursula Pole, Baroness Stafford (c. 1504 – 12 August 1570) was an English noblewoman; the wife of Henry Stafford, 1st Baron Stafford; a wealthy heiress and the only daughter of Margaret Pole, 8th Countess of Salisbury.
Her mother was the last surviving member of the Plantagenet dynasty and was executed for treason at the age of 67 in 1541 by the command of King Henry VIII.
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.
Henry Stafford, 1st Baron Stafford
Henry Stafford, 1st Baron Stafford (18 September 1501 – 30 April 1563) was born in Penshurst, Kent, eldest son of Edward Stafford, 3rd Duke of Buckingham and Eleanor Percy, Duchess of Buckingham.
Eleanor (or Alianore) was the daughter of Henry Percy, 4th Earl of Northumberland and Maud Herbert, Countess of Northumberland.
After his father's execution he managed to regain some of his family's position and he was created Baron Stafford in 1547.
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.
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.

Question: Who is the mother-in-law of Ursula Pole, Baroness Stafford?
Answer: Eleanor Percy, Duchess of Buckingham