Beatrix of Berg
Beatrix (Beatrice) of Berg (1364 in Burg on the Wupper–May 16, 1395 in Neustadt an der Weinstrasse) was the daughter of Duke William II of Berg and Electress of the Palatinate by marriage to Rupert I, Elector Palatine.
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.
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.
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.
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.
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.
Rupert I, Elector Palatine
Rupert I "the Red", Elector Palatine (9 June 1309, Wolfratshausen – 16 February 1390, Neustadt an der Weinstraße) was Count Palatine of the Rhine from 1353 to 1356, and Elector Palatine from 10 January 1356 to 16 February 1390.
He was the son of Rudolf I, Duke of Bavaria and Mechtild of Nassau, the daughter of King Adolf of Nassau-Weilburg.
With the death of his brother, Rudolf II, on 4 October 1353, he inherited his domains and became sole Count for the territory, whereas they had previously shared that privilege.
The Golden Bull of 1356 guaranteed the Palatinate the right of participating in the election of the Holy Roman Emperor.
Previous Counts Palatine had participated in other Imperial elections.
In 1386, Rupert founded Heidelberg University, the third university in the Holy Roman Empire, which was named after him.
Rupert was married twice: firstly to Elisabeth, Countess of Namur (daughter of John I, Marquis of Namur), secondly to Beatrix of Jülich-Berg.
Neither marriage produced an heir.
He was succeeded by his nephew, Rupert II, Elector Palatine.
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.

Question: Who is the mother-in-law of Beatrix Of Berg?
Answer: Mechtild of Nassau