Diana Guardato
Diana Guardato was a member of the aristocratic Patrician Guardato family, and had three children with King Ferdinand I: Diana Guardato is the 16th- Great Grandmother of His Royal Highness Albert II of Belgium, 15th- Great Grandmother of His Majesty Juan Carlos
I of Spain, 17th- Great Grandmother of Philippe of Belgium, 14th- Great Grandmother of His Majesty Manuel II of Portugal, 16th- Great Grandmother of Grand Duke Henri, as well as many others.
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.
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.
Eleanor of Aragon, Queen of Portugal
Eleanor of Aragon (2 May 1402 – 19 February 1445) was queen consort of Portugal as the spouse of Edward I of Portugal and the regent of Portugal as the guardian of her son.
She was the daughter of Ferdinand I of Aragon and Eleanor of Alburquerque.
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.
Jean de Metz
Jean de Metz( also Jean de Nouillonpont)( born c. 1398) was a French nobleman who is known primarily for his role in the exploits of Joan of Arc.
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.
Jean Pasquerel
Jean Pasquerel( c. 1400) was an Augustinian friar( member of the Order of St. Augustine), almoner and confessor of Joan of Arc.
Joan of Portugal
Joana of Portugal (31 March 1439 – June 13, 1475) was Queen consort of Castile as the second wife of King Henry IV of Castile and a Portuguese infanta, the posthumous daughter of King Edward of Portugal and his wife Eleanor of Aragon.
She was born in the Quinta do Monte Olivete Villa, Almada six months after the death of her father.
Hannah Arnold
Hannah Arnold, also known as Hannah Waterman King, was the grandmother of Benedict Arnolds children.

Question: Who is the maternal grandmother of Joan Of Portugal?
Answer: Eleanor of Alburquerque