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.
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.
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.
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.
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.
Hemma
Emma of Altdorf, also known as Hemma (– 31 January 876), a member of the Elder House of Welf, was Queen consort of East Francia by marriage to King Louis the German, from 843 until her death.
Louis the German
Louis the German (c. 806/810 – 28 August 876), also known as Louis II, was the first king of East Francia, and ruled from 843876 AD.
Grandson of emperor Charlemagne and the third son of Louis the Pious, emperor of Francia, and his first wife, Ermengarde of Hesbaye, he received the appellation "Germanicus" shortly after his death in recognition of Magna Germania of the Roman Empire, reflecting the Carolingian's assertions that they were the rightful descendants of the Roman Empire.
After protracted clashes with his father and his brothers, Louis received the East Frankish Empire in the 843 Treaty of Verdun.
His attempts to conquer the West Frankish Empire of his half-brother Charles the Bald in 858–59 were unsuccessful.
The 860s were marked by a severe crisis, with the East Frankish rebellions of the sons, as well as struggles to maintain supremacy over his realm.
In the Treaty of Meerssen he acquired Lotharingia for the East Frankish Empire in 870.
On the other hand, he tried and failed to claim both the title of Emperor and Italy.
In the East, Louis was able to reach a longer-term peace agreement in 874 after decades of conflict with the Moravians.
Due to a decline in the written form in administration and government, Louis' reign predates Ottonian times.
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.
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.

Question: Who is Hemma's mother-in-law?
Answer: Ermengarde of Hesbaye