Question: Who is the mother-in-law of Sophie Magdalene Of Brandenburg-Kulmbach?

Christian VI of Denmark
Christian VI (30 November 1699 – 6 August 1746) was King of Denmark and Norway from 1730 to 1746.
The eldest surviving son of King Frederick IV and Louise of Mecklenburg-Güstrow, he is considered one of Denmark-Norway's more anonymous kings, but he was a skilled politician, best known for his authoritarian regime.
He was the first king of the Oldenburg dynasty to refrain from entering in any war.
During his reign both compulsory confirmation (1736) and a public, nationwide school system (1739) were introduced.
His chosen motto was "deo et populo" (for God and the people).
Sophie Magdalene of Brandenburg-Kulmbach
Sophie Magdalene of Brandenburg-Kulmbach (28 November 1700 – 27 May 1770) was queen-consort of Denmark and Norway by marriage to King Christian VI of Denmark and Norway.
Kunigunde of Brandenburg-Kulmbach
Kunigunde of Brandenburg- Kulmbach( 1524 in Ansbach; died: 27 February 1558 in Pforzheim) was a princess of Brandenburg- Kulmbach by birth and by marriage Margravine of Baden- Durlach.
Frederick Ernest of Brandenburg-Kulmbach
Frederick Ernest of Brandenburg- Kulmbach( 15 December 1703 – 23 June 1762 in Drage) was a member of the Brandenburg- Kulmbach branch of the House of Hohenzollern.
His most significant position was governor of the Duchies of Schleswig and Holstein- Glückstadt.
Margaret of Baden
Margaret of Baden( 1431 – 24 October 1457) was a Margravine of Baden by birth and by marriage Margravine of Brandenburg- Ansbach and Brandenburg- Kulmbach.
She was the daughter of Jacob, Margrave of Baden- Baden, and his wife Catherine of Lorraine.
In 1446, Margaret married Albert of Brandenburg, the future Albert III Achilles, Elector of Brandenburg, in Heilsbronn.
Margaret died before he succeeded to the Electorate of Brandenburg, thus never served as Electress.
Their marriage produced three sons and three daughters:
Margaret died in Ansbach in 1457 shortly after her husband acquired the Margraviate of Brandenburg- Kulmbach.
Magdalene of Brandenburg (1412–1454)
Magdalene of Brandenburg( born:; died: 27 October 1454 in Scharnebeck) was a princess of Brandenburg by birth and by marriage Duchess of Brunswick- Lüneburg.
Elisabeth of Brandenburg-Küstrin
Elizabeth of Brandenburg- Küstrin( 29 August 1540 – 8 March 1578), was a princess of Brandenburg- Küstrin and margravine of Brandenburg- Ansbach and Brandenburg- Kulmbach by marriage.
Marie of Brandenburg-Kulmbach
Marie of Brandenburg- Kulmbach( born 14 October 1519 in Ansbach – died 31 October 1567 in Heidelberg) was a Princess of Brandenburg- Kulmbach and by marriage Electress Palatine.
Bernhard Ditlef von Staffeldt
Bernhard Ditlef von Staffeldt was born on 23 October 1753 in Kenz, Swedish Pomerania as the son of Lieutenant Bernt von Staffeldt, of Pomeranian nobility, and Catherine Eleonore von Platen.
Both his parents died in 1755 while he was still a child so he was raised at his married sisters estate in Denmark, and was taken into the court of Queen Sophia Magdalene of Brandenburg- Kulmbach in 1767.
Frederick V of Denmark
Frederick V( Danish and Norwegian:" Frederik"; 31 March 172314 January 1766) was king of Denmark – Norway and Duke of Schleswig- Holstein from 1746 until his death.
He was the son of Christian VI of Denmark and Sophie Magdalene of Brandenburg- Kulmbach.

Answer: Louise of Mecklenburg-Güstrow