Mary Elizabeth Donaldson was born on February 5, 1972, in Hobart, Tasmania, Australia. The youngest of four children, she graduated from the University of Tasmania with a bachelor’s degree in Commerce and Law. During the 2000 Sydney Olympics, Mary met Denmark’s Crown Prince Frederik at a Sydney inner-city bar called “The Slip Inn”. On 24 September 2003, it was announced that Frederik's mother, Queen Margrethe II of Denmark, intended to give her consent to the marriage at the State Council meeting scheduled for 8 October 2003. Subsequently, as per royal protocol, she renounced her Australian citizenship and converted from Presbyterianism to the Lutheran Church of Denmark. The wedding was held on May 14, 2004, at Copenhagen Cathedral.

Upon her marriage, Mary became “Her Royal Highness, The Crown Princess of Denmark”. She was also honoured with the Order of the Elephant, a Danish order of chivalry and Denmark's highest-ranked honour.

Frederik and Mary have four children: Prince Christian Valdemar Henri John, born 15 October 2005; Princess Isabella Henrietta Ingrid Margrethe, born 21 April 2007; and twins Prince Vincent Frederik Minik Alexander and Princess Josephine Sophia Ivalo Mathilda, born 8 January 2011 and all of them born at Rigshospitalet in Copenhagen.

Maxima and Letizia are the Queens of the Netherlands and Spain respectively. Victoria is the Crown Princess of Sweden.

When Frederik becomes king, Mary would automatically become the Queen Consort of Denmark.

More Info: en.wikipedia.org