Princess Pilar of Bavaria
Princess Pilar of Bavaria ("Maria del Pilar Eulalia Antonia Isabella Ludovika
Franziska Josepha Rita Euphrasia von Wittelsbach, princess of Bavaria")
(March 13, 1891 – January 29, 1987) was the only daughter of Prince Ludwig Ferdinand of Bavaria and his wife Infanta Maria de la Paz of Spain.
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.
Hannah Arnold
Hannah Arnold, also known as Hannah Waterman King, was the grandmother of Benedict Arnolds children.
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.
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.
Infanta María de la Paz of Spain
Infanta María de la Paz of Spain ("María de la Paz de Borbón y Borbón"
; Madrid, 23 June 1862 – Schloss Nymphenburg, Munich, 4 December 1946) was an infanta of Spain.
A daughter of Queen Isabella II of Spain, she married her first cousin Prince Ludwig Ferdinand of Bavaria.
She lived for the rest of her life in Germany, dedicating her time to her family, charity work and writing poetry.
She wrote a book of memoirs: "Through Four Revolutions: 1862–1933".
Duchess Marie Gabrielle in Bavaria
Duchess Marie Gabrielle in Bavaria( 9 October 1878 in Tegernsee, Bavaria – 24 October 1912 in Sorrento, Italy) was the youngest daughter of Duke Karl Theodor in Bavaria and his second wife, Infanta Maria Josepha of Portugal.
She married Prince Rupprecht of Bavaria in 1900 but died before he became Crown Prince.
Through her second son Albrecht, Marie Gabrielle was the grandmother of the present Duke of Bavaria, Franz.
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.
Gülbahar Hatun (wife of Mehmed II)
Gülbahar Hatun( 1432 – 1492) was the consort of Sultan Mehmed II, and mother of Sultan Bayezid II of the Ottoman Empire and the grandmother of Selim I.
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 Princess Pilar Of Bavaria?
Answer: Isabella II of Spain