Prince Vincent of Denmark, Count of Monpezat (Vincent Frederik Minik Alexander; born 8 January 2011), is the third child and younger son of Crown Prince Frederik and Crown Princess Mary, the sixth grandchild and youngest grandson of Queen Margrethe II and Prince Henrik, and the twin brother of Princess Josephine.
A crown prince or crown princess is the heir apparent to the throne in a royal or imperial monarchy.
 The wife of a crown prince is also styled crown princess.
John Dalgleish Donaldson (born 5 September 1941) is a Scottish-Australian professor and the father of Mary, Crown Princess of Denmark, the wife of the heir apparent to the throne of Denmark, Frederik, Crown Prince of Denmark.
Princess Josephine of Denmark, Countess of Monpezat (Josephine Sophia Ivalo Mathilda; born 8 January 2011), is the fourth and youngest child of Crown Prince Frederik and Crown Princess Mary, and the seventh grandchild of Queen Margrethe II of Denmark and her husband, Henrik, Prince Consort of Denmark.
 She is the twin sister of Prince Vincent of Denmark.
Mary, Crown Princess of Denmark, Countess of Monpezat, {'1': ", '2': ", '3': 'R.E.', '4': "} (Mary Elizabeth; "née" Donaldson; born 5 February 1972) is the wife of Frederik, Crown Prince of Denmark.
 Frederik is the heir apparent to the throne, which means that should Frederik succeed, she will automatically become Queen of Denmark.
Yaza Datu Kalaya (Burmese: ရာဇ ဓာတု ကလျာ , ] ; also spelled Yaza Datu Kalya; 12 November 1559 – November 1603) was crown princess of Burma from 1586 to 1593, and crown princess of Toungoo for seven months in 1603.
 Known for her great beauty, the princess was also a noted poet, and the subject of some of the "most beautiful poems in Burmese literature" by Natshinnaung.
Frederik, Crown Prince of Denmark, Count of Monpezat, {'1': ", '2': ", '3': 'RE, SKmd', '4': "} (Frederik André Henrik Christian; born 26 May 1968) is the heir apparent to the throne of Denmark.
 Frederik is the elder son of Queen Margrethe II and Henrik, the Prince Consort.
Crown Princess is a "Grand"-class cruise ship owned and operated by Princess Cruises.
 Her maiden voyage took place on June 14, 2006, departing Red Hook, Brooklyn (New York) for Grand Turk (Turks & Caicos), Ocho Rios (Jamaica), Grand Cayman (Cayman Islands), and Port Canaveral (Florida).
 As of 2015, the "Crown Princess" sails to Mexico for the Winter season, and Alaska for the Summer season.
 Like her sister ships "Emerald Princess" and "Ruby Princess" her Skywalkers Night Club is built aft of the funnel rather than suspended over the stern.
 Her godmother is Martha Stewart.
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.
Princess Isabella of Denmark, Countess of Monpezat (Isabella Henrietta Ingrid Margrethe; born 21 April 2007), is the second child and elder daughter of Crown Prince Frederik and Crown Princess Mary.

Question: Who is Mary, Crown Princess of Denmark's mother-in-law?
Answer: Queen Margrethe II