Diana Guardato
Diana Guardato was a member of the aristocratic Patrician Guardato family, and had three children with King Ferdinand I: Diana Guardato is the 16th- Great Grandmother of His Royal Highness Albert II of Belgium, 15th- Great Grandmother of His Majesty Juan Carlos
I of Spain, 17th- Great Grandmother of Philippe of Belgium, 14th- Great Grandmother of His Majesty Manuel II of Portugal, 16th- Great Grandmother of Grand Duke Henri, as well as many others.
Duke Franz Joseph in Bavaria
Duke Franz Joseph in Bavaria, full German name:" Franz Joseph Michael Karl
Maria Evaristus Quirinus Ottokar Herzog in Bayern"( 23 March 1888, Schloss Tegernsee, Kingdom of Bavaria – 23 September 1912, Munich, Kingdom of Bavaria) was a Duke in Bavaria and member of the House of Wittelsbach.
Franz Joseph was the fifth and youngest child of Duke Karl- Theodor in Bavaria and his wife Infanta Maria Josepha of Portugal.
Franz Joseph was the brother of Duke Ludwig Wilhelm in Bavaria and sisters Duchess Amalie in Bavaria, Duchess Sophie Adelheid in Bavaria, Duchess Elisabeth in Bavaria and Duchess Marie Gabrielle in Bavaria.
Anne Denman
Anne Denman( 1587–1661) was born in Olde Hall, Retford, Nottinghamshire.
Through a fortunate second marriage with Thomas Aylesbury, she became the grandmother of Lady Anne Hyde, Duchess of York and great- grandmother of Queen Mary II and Queen Anne.
Hubba bint Hulail
Hubba bint Hulail was the grandmother of Hashim ibn' Abd Manaf, thus the great- great- great- grandmother of the Islamic" Nabī"( Prophet) Muhammad ibn Abdullah.
Duchess Amalie in Bavaria
Duchess "Amalie" Maria in Bavaria
(Full German name: "
Amalie Maria, Herzogin in Bayern") (24 December 1865 – 26 May 1912) was born in Munich, Kingdom of Bavaria, the only child of Duke Karl-Theodor in Bavaria and his first wife Princess Sophie of Saxony.
Amalie was a member of the House of Wittelsbach and a Duchess in Bavaria by birth.
She was a member of the House of Württemberg, Duchess of Urach and Countess of Württemberg through her marriage to Wilhelm, 2nd Duke of Urach.
She was called by the French version of her name, Amélie, and was lifelong friends with her cousin, Archduchess Marie Valerie of Austria.
Hannah Arnold
Hannah Arnold, also known as Hannah Waterman King, was the grandmother of Benedict Arnolds children.
Mona Hopton Bell
Mona Hopton Bell( 1867- 1940) was a British artist, best known for her portraits of civic figures.
She was the grandmother of the painter Jean H. Bell.
Princess Sophie of Saxony
Princess "Sophie" Maria Friederike Auguste Leopoldine Alexandrine Ernestine Albertine Elisabeth of Saxony, Duchess of Saxony (Full German name: "
Prinzessin Sophie Maria Friederike Auguste Leopoldine Alexandrine Ernestine Albertine Elisabeth von Sachsen, Herzogin zu Sachsen") (15 March 1845, Dresden, Kingdom of Saxony – 9 March 1867, Munich, Kingdom of Bavaria) was the eighth and youngest child of John of Saxony and his wife Amalie Auguste of Bavaria and a younger sister of Albert of Saxony and George of Saxony.
Through her marriage to Duke Karl-Theodor in Bavaria, Sophie was a member of the House of Wittelsbach and a Duchess in Bavaria.
Tjuyu
Tjuyu( sometimes transliterated as Thuya or Thuyu) was an Egyptian noblewoman and the mother of queen Tiye, and the wife of Yuya.
She is the grandmother of Akhenaten, and great grandmother of Tutankhamun.
Kaoru Hatoyama
After the elections of 2009, she became more widely known as the grandmother of Prime Minister Yukio Hatoyama and his politician brother Kunio Hatoyama.

Question: Who is the maternal grandmother of Duchess Amalie In Bavaria?
Answer: Amalie Auguste of Bavaria