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.
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.
Gian Galeazzo Visconti
Gian Galeazzo Visconti (16 October 1351 – 3 September 1402), son of Galeazzo II Visconti and Bianca of Savoy, was the first Duke of Milan (1395) and ruled the late-medieval city just before the dawn of the Renaissance.
He was the founding patron of the Certosa di Pavia, completing the Visconti Castle at Pavia begun by his father and furthering work on the Duomo of Milan.
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.
Gian Maria Visconti
Gian Maria Visconti (or Giovanni Maria; 7 September 1388 in Abbiategrasso – 16 May 1412) was the second Visconti Duke of Milan, the son of Gian Galeazzo Visconti and Caterina Visconti.
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.
Caterina Visconti
Caterina Visconti (1361 – 17 October 1404) was Duchess of Milan as the second spouse of Gian Galeazzo Visconti, the first Duke of Milan, and was the mother of two succeeding Dukes of Milan, Gian Maria and Filippo Maria Visconti.
Caterina served as Regent of Milan from 1402 to 1404, during her elder son's minority, but due to Gian Maria's suspicion of her alleged treason (planted in his mind by her enemy, the condottiero Facino Cane), he had his mother arrested and imprisoned in the castle of Monza, where she was presumably poisoned in 1404.
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.
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 Gian Maria Visconti's paternal grandmother?
Answer: Bianca of Savoy