Question: Major Ronald Ferguson's wife is the maternal grandmother of which two women?
Context: Christine Louise of Oettingen-Oettingen (20 March 1671 in Oettingen – 3 September 1747 in Blankenberg) was Duchess of Brunswick-Lüneburg.  She was the maternal grandmother of Holy Roman Empress Maria Theresa, Queen Elisabeth Christine of Prussia, Queen Juliane Marie of Denmark and Norway and Tsar Peter II of Russia; the maternal great-grandmother of Queen Marie Antoinette of France, Tsar Ivan VI of Russia and Francis, Duke of Saxe-Coburg-Saalfeld; the maternal great-great-grandmother of King Leopold I of Belgium and the maternal great-great-great-grandmother of Queen Victoria of the United Kingdom. Sarah, Duchess of York (Sarah Margaret; "née" Ferguson; born 15 October 1959) is a British writer, charity patron, public speaker, film producer and television personality.  She is the former wife of Prince Andrew, Duke of York, the second son of Queen Elizabeth II and Prince Philip, Duke of Edinburgh.  She is the younger daughter of Major Ronald Ferguson and Susan Barrantes (née Wright).  Sarah has two daughters, Princesses Beatrice and Eugenie of York, who are respectively seventh and eighth in the line of succession to the British throne. Alice Holland, Countess of Kent (c. 1350 – 17 March 1416), LG, formerly Lady Alice FitzAlan, was an English noblewoman, a daughter of the 10th Earl of Arundel, and the wife of the 2nd Earl of Kent, the half-brother of King Richard II.  As the maternal grandmother of Anne Mortimer, she was an ancestor of King Edward IV and King Richard III, as well as King Henry VII and the Tudor dynasty through her daughter Margaret Holland.  She was also the maternal grandmother of Joan Beaufort, Queen of Scotland. Antonia Minor ("PIR" A 885), also known as Julia Antonia Minor, Antonia the Younger or simply Antonia (31 January 36 BC - September/October AD 37) was the younger of two daughters of Mark Antony and Octavia Minor.  She was a niece of the Emperor Augustus, sister-in-law of the Emperor Tiberius, paternal grandmother of the Emperor Caligula and Empress Agrippina the Younger, mother of the Emperor Claudius, and both maternal great-grandmother and paternal great-aunt of the Emperor Nero.  She was additionally the maternal great-aunt of the Empress Valeria Messalina and Faustus Cornelius Sulla Felix, the paternal grandmother of Claudia Antonia, Claudia Octavia, and Britannicus and the maternal grandmother of Julia Livia and Tiberius Gemellus. Major Ronald Ivor Ferguson (10 October 1931 – 16 March 2003) was the father of Sarah, Duchess of York, former wife to the Duke of York.  He is the maternal grandfather of Princesses Beatrice and Eugenie of York.  Major Ferguson was polo manager, initially to the Duke of Edinburgh and later, for many years, to the Prince of Wales. Cotys IX or Kotys IX (name in Greek: ο Κότυς, flourished 1st century) was a Thracian prince and the Roman Client King of Lesser Armenia.  Cotys was the second son and was among the children of Roman Client Rulers of Thrace Cotys VIII and Antonia Tryphaena.  His paternal grandparents were loyal Roman Client Rulers Rhoemetalces I and Pythodoris I of Thrace, while his maternal grandparents Roman Client Rulers Polemon Pythodoros and Pythodorida of Pontus.  Cotys was the namesake of his father and was of Persian, Greek and Roman descent.  His maternal grandmother Pythodorida of Pontus was the first grandchild of Roman Triumvir Mark Antony.  Thus through his maternal grandmother, Cotys was related to various members of the Julio-Claudian dynasty. Octavia the Younger (69 BC – 11 BC), also known as Octavia Minor or simply Octavia, was the elder sister of the first Roman Emperor, Augustus (known also as Octavian), the half-sister of Octavia the Elder, and the fourth wife of Mark Antony.  She was also the great-grandmother of the Emperor Caligula and Empress Agrippina the Younger, maternal grandmother of the Emperor Claudius, and paternal great-grandmother and maternal great-great grandmother of the Emperor Nero. Susan Mary Barrantes ("née" Wright, previously Ferguson; 9 June 1937 – 19 September 1998) was the mother of Sarah, Duchess of York, and the maternal grandmother of Princesses Beatrice and Eugenie of York. Prince Hermann Friedrich of Leiningen (born 16 April 1963) is the younger son of Prince Karl of Leiningen and his wife Princess Marie Louise of Bulgaria.  Hermann was born in Toronto, Ontario, as Hermann Friedrich Fernando Roland.  Through his mother, Hermann is a grandson of King Boris III of Bulgaria, a great-grandson of King Victor Emmanuel III of Italy and -great-great-grandson of King Nicholas of Montenegro.  Through his father, he is a great-great-great grandson of Queen Victoria (thus in the line of succession to the British throne), as well as Tsar Alexander II of Russia.  According to Marlene Eilers, Hermann of Leiningen belongs to the Eastern Orthodox Church.  His paternal grandmother was Grand Duchess Maria Kirillovna Romanova of Russia and his maternal grandmother was Princess Giovanna of Savoia, daughter of King Victor Emmanuel III of Italy. Margaret Katherine Majer (December 13, 1898 – January 6, 1990) was an American Instructor of physical education for women and first coach of women's teams at Penn.  She was the wife of Jack Kelly, three-time Olympic Gold Medal winner in Rowing, and mother of Grace Kelly, actress and Princess of Monaco (thus maternal grandmother of Albert II, Prince of Monaco), and of John B. Kelly Jr., an accomplished rower.
Answer: Princesses Beatrice and Eugenie of York