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.
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.
Hannah Arnold
Hannah Arnold, also known as Hannah Waterman King, was the grandmother of Benedict Arnolds children.
Sigurd Snake-in-the-Eye
Sigurd Snake-in-the-eye  was a Viking warrior and Danish King active from the mid to late 9th Century.
According to multiple Saga sources and Scandinavian histories he is one of the sons of the legendary Viking Ragnar Lodbrok and Aslaug.
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.
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.
Christina of Saxony
Christina of Saxony( b. Torgau, 25 December 1461 – d. Odense, 8 December 1521), was Queen consort of Denmark, Norway, and Sweden.
She was born a granddaughter of Frederick the Gentle of Saxony, and daughter of Ernest, Elector of Saxony and Elisabeth of Bavaria.
She was the grandmother of Christina of Denmark through her son Christian II.
Princess Caroline-Mathilde of Denmark
Princess Caroline- Mathilde of Denmark( 27 April 1912 – 12 December 1995) was a daughter of Prince Harald of Denmark and granddaughter of King Frederick VIII of Denmark.
As the wife of Knud, Hereditary Prince of Denmark, she became Hereditary Princess of Denmark.
Harthacnut I of Denmark
Harthacnut or Cnut
I  (born c. 880) was a semi-legendary King of Denmark.
"
Ragnarssona þáttr" makes Harthacnut son of the semi-mythic viking chieftain Sigurd Snake-in-the-Eye, himself one of the sons of the legendary Ragnar Lodbrok.
The saga in turn makes Harthacnut the father of the historical king, Gorm.
It has been suggested he is to be identified with the Hardegon of "Northmannia" whose early-10th century conquest of Denmark was related by Adam of Bremen.

Question: Who is Harthacnut I Of Denmark's paternal grandmother?
Answer: Aslaug