Maria d'Este
Maria d'Este (8 December 1644 – 20 August 1684) was a Modenese princess and Duchess of Parma as the wife of Ranuccio II Farnese, Duke of Parma.
She was a daughter of Francesco I d'Este, Duke of Modena and Maria Caterina Farnese.
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.
Hüma Hatun
Hüma Hatun (1410 ‒ September 1449) was the fourth wife of Ottoman Sultan Murad II and mother of Mehmed II and the grandmother of Bayezid II.
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.
Hannah Arnold
Hannah Arnold, also known as Hannah Waterman King, was the grandmother of Benedict Arnolds children.
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.
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.
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.
Francesco Farnese, Duke of Parma
Francesco Farnese (19 May 1678 – 26 February 1727) reigned as the seventh Farnese Duke of Parma and Piacenza from 1694 until his death.
Married to Dorothea Sophia of the Palatinate, his brother Odoardo's widow, to avoid the return of her dowry, Francesco curtailed court expenditure, enormous under his father and predecessor, Ranuccio II, while preventing the occupation of his Duchy of Parma, nominally a Papal fief, during the War of the Spanish Succession.
The second son of Ranuccio II Farnese and Maria d'Este of Modena, the Duke, despite his efforts otherwise, saw Parma declared a fief of the Duchy of Milan, an Austrian province in Italy, towards the end of the war.
His inability to produce offspring, combined with his brother Antonio's barrenness, lead to the accession of his niece the Queen of Spain's eldest son, Don Carlos, in 1731.

Question: Who is the maternal grandmother of Francesco Farnese, Duke Of Parma?
Answer: Maria Caterina Farnese