Rotrude
Rotrude (or sometimes referred to as Hruodrud/Hruodhaid)
(775/778 – 6 June 810) was a Frankish princess, the second daughter of Charlemagne from his marriage to Hildegard.
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.
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.
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.
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.
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.
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.
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.
Charlemagne
Charlemagne  or Charles the Great (2 April 748 – 28 January 814), numbered Charles I, was King of the Franks from 768, King of the Lombards from 774, and Emperor of the Romans from 800.
During the Early Middle Ages, he united the majority of western and central Europe.
He was the first recognised emperor to rule from western Europe since the fall of the Western Roman Empire three centuries earlier.
The expanded Frankish state that Charlemagne founded is called the Carolingian Empire.
He was later canonized by Antipope Paschal III.
Charlemagne was the eldest son of Pepin the Short and Bertrada of Laon, born before their canonical marriage.
He became king in 768 following his father's death, initially as co-ruler with his brother Carloman I. Carloman's sudden death in December 771 under unexplained circumstances left Charlemagne the sole ruler of the Frankish Kingdom.
He continued his father's policy towards the papacy and became its protector, removing the Lombards from power in northern Italy and leading an incursion into Muslim Spain.
He campaigned against the Saxons to his east, Christianizing them upon penalty of death and leading to events such as the Massacre of Verden.
He reached the height of his power in 800 when he was crowned "Emperor of the Romans" by Pope Leo III on Christmas Day at Rome's Old St. Peter's Basilica.
Charlemagne has been called the "Father of EuropePater Europae"), as he united most of Western Europe for the first time since the classical era of the Roman Empire and united parts of Europe that had never been under Frankish or Roman rule.
His rule spurred the Carolingian Renaissance, a period of energetic cultural and intellectual activity within the Western Church.
Emperors of the Holy Roman Empire considered themselves successors of Charlemagne, as did the French and German monarchs.
The Eastern Orthodox Church viewed Charlemagne less favorably due to his support of the filioque and the Pope's having preferred him as Emperor over the Byzantine Empire's Irene of Athens.
These and other disputes led to the eventual split of Rome and Constantinople in the Great Schism of 1054.
Charlemagne died in 814 and was laid to rest in his imperial capital city of Aachen.
He married at least four times and had three legitimate sons who lived to adulthood, but only the youngest of them, Louis the Pious, survived to succeed him.

Question: Who is the paternal grandmother of Rotrude?
Answer: Bertrada of Laon