Prince Frederick of Prussia (1911–1966)
Prince Frederick of Prussia( 19 December 1911 – 20 April 1966), also known as" Mr. Friedrich von Preussen" in the United Kingdom, was the fourth son of Crown Prince Wilhelm of Germany and Duchess Cecilie of Mecklenburg- Schwerin.
Prince Friedrich Wilhelm of Prussia
Prince Friedrich Wilhelm of Prussia( 12 July 18809 March 1925) was a member of the House of Hohenzollern, great- grandson of Frederick William III of Prussia.
Princess Marianne of Prussia
Princess Marianne of Prussia( 23 August 19131 March 1983) was a member of the House of Hohenzollern, daughter of Prince Friedrich Wilhelm of Prussia.
Duchess Cecilie of Mecklenburg-Schwerin
Duchess Cecilie of Mecklenburg-Schwerin (Cecilie Auguste Marie; 20 September 1886 – 6 May 1954) was the last German Crown Princess and Crown Princess of Prussia as the wife of German Crown Prince Wilhelm, the son of German Emperor Wilhelm II.
Cecilie was a daughter of Frederick Francis III, Grand Duke of Mecklenburg-Schwerin and Grand Duchess Anastasia Mikhailovna of Russia.
She was brought up with simplicity and her early life was peripatetic, spending summers in Mecklenburg and the rest of the year in the south of France.
After the death of her father, she traveled every summer between 1898 and 1904 to her mother's native Russia.
On 6 June 1905, she married German Crown Prince Wilhelm.
The couple had four sons and two daughters.
Cecile, tall and statuesque, became popular in Germany for her sense of style.
However, her husband was a womanizer and the marriage was unhappy.
After the fall of the German monarchy, at the end of World War I, Cecile and her husband lived mostly apart.
During the Weimar Republic and the Nazi period, Cecilie lived a private life mainly at Cecilienhof Palace in Potsdam.
With the advance of the Soviet troops, she left the Cecilienhof in February 1945, never to return.
She settled in Bad Kissingen until 1952 when she moved to an apartment in the Frauenkopf district of Stuttgart.
In 1952, she published a book of memoirs.
She died two years later.
Prince Hubertus of Prussia
Prince Hubertus of Prussia (Hubertus Karl Wilhelm; 30 September 1909 – 8 April 1950) was the third son of Crown Prince Wilhelm of Germany and Duchess Cecilie of Mecklenburg-Schwerin.
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.
Princess Elisabeth of Prussia
Princess Elisabeth of Prussia( 18 June 1815 – 21 March 1885) was the second daughter of Prince Wilhelm of Prussia and Landgravine Marie Anna of Hesse- Homburg and a granddaughter of Frederick William II of Prussia.
Prince Philip, Duke of Edinburgh is her great- great- grandson.
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.
Prince Wilhelm of Prussia (1906–1940)
Prince Wilhelm of Prussia (Wilhelm Friedrich Franz Joseph Christian Olaf; 4 July 1906 – 26 May 1940) was the eldest child of Crown Prince Wilhelm of Germany and Duchess Cecilie of Mecklenburg-Schwerin.
At his birth, he was second in line to the German throne and was expected to succeed to the throne after the deaths of his paternal grandfather and father.
Both of whom, however, outlived him.
Prince Wilhelm of Hesse-Philippsthal-Barchfeld
Prince Wilhelm of Hesse(" Wilhelm Ernst Alexis Hermann"; 1 March 1905 – 30 April 1942) was German soldier and heir to the headship of the Hesse- Philippsthal line of the House of Hesse.
As a member of the House of Hesse he was styled" His Highness Prince Wilhelm of Hesse".

Question: Who is Prince Wilhelm Of Prussia (1906–1940)'s maternal grandmother?
Answer: Grand Duchess Anastasia Mikhailovna of Russia