Bolesław IV of Legnica
Bolesław IV of Legnica( ca. 1349 – 3/4 March 1394) was a Duke of Legnica since 1364( nominally; together with his brothers).
He was the third son of Wenceslaus I, Duke of Legnica by his wife Anna, daughter of Casimir I, Duke of Cieszyn.
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.
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.
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 VIII of Legnica
Henry VIII of Legnica( ca. 1355 – 12 December 1398) was a Duke of Legnica since 1364( nominally and together with his brothers) and Bishop of Włocławek since 1389 until his death.
He was the fourth of Wenceslaus I, Duke of Legnica, by his wife Anna, daughter of Casimir I, Duke of Cieszyn.
John George, Elector of Brandenburg
John George of Brandenburg  (11 September 1525 – 8 January 1598) was a Prince-elector of the Margraviate of Brandenburg (1571–1598) and a Duke of Prussia.
A member of the House of Hohenzollern, he was the son of Joachim II Hector, Elector of Brandenburg, and his first wife Magdalena of Saxony.
Faced with large debts accumulated during the reign of his father, John George instituted a grain tax which drove part of the peasantry into dependence on a nobility that was exempt from taxation.
Though a staunch Lutheran opposed to the rise of Calvinism, he permitted the admission of Calvinist refugees from the wars in the Spanish Netherlands and France.
He was succeeded by his son Joachim Frederick.
Upon the death of his kinsman Albert I, Duke of Prussia in 1568, the Duchy of Prussia was inherited by the latter's underage son Albert Frederick.
John George's father was a co-inheritor of the Duchy of Prussia.
In 1577 the Brandenburg electors became co-regent with Duke Albert Frederick of Prussia.
Sophie of Legnica
Sophie of Legnica (1525 – 6 February 1546) was a daughter of Frederick II, Duke of Legnica, Brzeg, and Wohlau, and his second wife, Sophie of Brandenburg-Ansbach-Kulmbach (1485 – 1537).
Sophie, who was brought up as a Protestant, married the future Elector John George of Brandenburg on 15 February 1545.
She died before he acceded to the Electorate and never reigned as Electress of Brandenburg.
Her son (and only child)
Joachim Frederick did, however, accede to the Electorate in 1598.
Frederick II of Legnica
Frederick II, Duke of Legnica( 12 February 1480 – 17 September 1547), also known as the Great of Legnica, was a Duke of Legnica from 1488( until 1495 and 1505 with his brothers), of Brzeg from 1521.
The most notorious of all Legnica Piast rulers, thanks to his excellent financial politics his Duchy was expanded to the Oder River, and he became the founder of the Duchy of Legnica- Wołów- Brzeg.
He was the second son of Frederick I, Duke of Chojnów- Oława- Legnica- Brzeg- Lubin, by his wife Ludmila, daughter of George of Poděbrady, King of Bohemia.

Question: Who is the mother-in-law of Sophie Of Legnica?
Answer: Magdalena of Saxony