Friedrich Franz, Hereditary Grand Duke of Mecklenburg-Schwerin
Friedrich Franz, Hereditary Grand Duke of Mecklenburg- Schwerin( 22 April 1910 – 31 July 2001) was the heir apparent to the throne of Mecklenburg- Schwerin and a member of the Waffen- SS.
Christian Louis I, Duke of Mecklenburg
Christian Louis I, Duke of Mecklenburg- Schwerin( 1 December 1623 in Schwerin – 21 June 1692 in The Hague) was a reigning Duke of Mecklenburg- Schwerin.
Karin Elisabeth von Schaper
Karin Elisabeth, Hereditary Grand Duchess of Mecklenburg- Schwerin( née" von Schaper", Karin Elisabeth Henriette Lori Gudela; 31 January 1920 – 26 January 2012) was a member by marriage of the House of Mecklenburg- Schwerin.
She was the widow of Friedrich Franz, Hereditary Grand Duke of Mecklenburg- Schwerin.
Duchess Marie Louise of Mecklenburg-Schwerin
Duchess Marie Louise of Mecklenburg-Schwerin (31 March 180326 October 1862) was daughter of Frederick Louis, Hereditary Grand Duke of Mecklenburg-Schwerin and consort of Georg, Duke of Saxe-Altenburg.
Duchess Louise Charlotte of Mecklenburg-Schwerin
Duchess Louise Charlotte of Mecklenburg- Schwerin( 19 November 1779 – 4 January 1801) was the maternal grandmother of Prince Albert, husband of Queen Victoria of the United Kingdom.
Louise Charlotte was born Duchess of Mecklenburg- Schwerin, her father being Friedrich Franz I, Grand Duke of Mecklenburg- Schwerin.
Her mother was Princess Louise of Saxe- Gotha- Altenburg; her sister Charlotte of Mecklenburg- Schwerin( 1784–1840) married King Christian VIII of Denmark.
Duke Louis of Mecklenburg-Schwerin
Duke Louis of Mecklenburg- Schwerin( 6 August 172512 September 1778) was heir to the Dukedom of Mecklenburg- Schwerin from 1756 to his death.
He was also the father of the first Grand Duke of Mecklenburg- Schwerin Frederick Francis I
Princess Louise of Saxe-Gotha-Altenburg (1756–1808)
Princess Louise of Saxe- Gotha -Altenburg,( born 9 March 1756 in Roda, Duchy of Saxe- Gotha- Altenburg; died 1 January 1808 at Schloss Ludwigslust in Ludwigslust, Duchy of Mecklenburg- Schwerin) was Duchess consort of Mecklenburg- Schwerin through her marriage to Frederick Francis I, Grand Duke of Mecklenburg, Louise was also a member of the House of Mecklenburg.
Frederick Louis, Hereditary Grand Duke of Mecklenburg-Schwerin
Frederick Louis of Mecklenburg-Schwerin (13 June 1778 – 29 November 1819) was a hereditary prince of the Grand Duchy of Mecklenburg-Schwerin, one of the constituent states of the German Confederation.
He was the son of Frederick Francis I, Grand Duke of Mecklenburg-Schwerin, and of Princess Louise of Saxe-Gotha-Altenburg.
Magnus II, Duke of Mecklenburg
Magnus II, Duke of Mecklenburg- Schwerin and Güstrow( 1441 – 20 November 1503) was duke of Mecklenburg- Schwerin from 1477 until his death.
Princess Alexandrine of Prussia (1803–1892)
Princess Alexandrine of Prussia( 23 February 1803 – 21 April 1892) was Grand Duchess of Mecklenburg- Schwerin by marriage to Paul Frederick, Grand Duke of Mecklenburg- Schwerin.
She was the daughter of Frederick William III of Prussia and Louise of Mecklenburg- Strelitz.

Question: Who is Duchess Marie Louise Of Mecklenburg-Schwerin's paternal grandmother?
Answer: Princess Louise of Saxe-Gotha-Altenburg