The Queen is the youngest daughter of John Dalgleish Donaldson, who was born in Scotland on 5 September 1941. He is a Professor of Applied Mathematics. The Queen's mother was Mrs. Henrietta Clark Donaldson, born 12 May 1942.

The couple were married in Edinburgh, Scotland on 31 August 1963 and emigrated to Australia in November that year. They became Australian citizens in 1975. The Queen's mother worked as the Executive Assistant to the Vice Chancellor of The University of Tasmania. Henrietta Clark Donaldson died 20 November 1997.

On 5 September 2001, Professor John Donaldson married Susan Elizabeth Donaldson (née Horwood), an author from Britain.

The Queen has two sisters and a brother: Jane Alison Stephens, born 26 December 1965, Patricia Anne Bailey, born 16 March 1968, and John Stuart Donaldson, born 9 July 1970.

Wedding
On 14 May 2004, on the occasion of the marriage to His Majesty The King (then His Royal Highness Crown Prince Frederik of Denmark), she became Her Royal Highness Crown Princess Mary Elizabeth of Denmark. The marriage ceremony took place in Copenhagen Cathedral, and the wedding festivities were held at Fredensborg Palace.

Children
HRH Crown Prince Christian Valdemar Henri John, born on 15 October 2005, HRH Princess Isabella Henrietta Ingrid Margrethe, born on 21 April 2007, HRH Prince Vincent Frederik Minik Alexander and HRH Princess Josephine Sophia Ivalo Mathilda, twins born on 8 January 2011.

Residence
The Royal Family resides both in Frederik VIII’s Palace at Amalienborg and in the Chancellery House at Fredensborg Palace.

The Queen’s schooling began in 1974 and 1975 at Clear Lake City Elementary School in Houston, Texas. Returning to Hobart, The Queen attended Sandy Bay Infants School from 1975 to 1977. From 1978 until 1982, Her Majesty attended Waimea Heights Primary School. The Queen attended Taroona High School from 1983 to 1986 and then during the next two years continued her studies at Hobart Matriculation College, where The Queen was also an active sportswoman. Her Majesty enrolled at the University of Tasmania in 1989 and graduated in 1994 with a Bachelor's degree in Commerce and Law (B Com. LLB).

Between 1994 and 1996, The Queen qualified for a Certificate in Advertising from The Advertising Federation of Australia (AFA) and later a Certificate in Direct Marketing from the Australian Direct Marketing Association.

Business background
After completion of her university degree, The Queen moved to Melbourne to take a graduate position with the world-wide advertising agency DDB Needham. After completion of the graduate programme, Her Majesty held the position of Account Executive for client management. The Queen's career path continued with a position as Account Manager with MOJO Partners, also in Melbourne. In 1998, The Queen travelled around America and also travelled extensively in Europe and the United Kingdom, particularly in her father’s homeland, Scotland, where Her Majesty accepted a three-month contract as Account Manager with Rapp Collins Worldwide of Edinburgh.

The Queen returned to Australia in the beginning of 1999 and took a position as Account Director with the international advertising agency Young and Rubicam in Sydney. The Queen later worked for a short time with a smaller Australian company, Love, and Her Majesty later became Sales Director and a member of the Management Team with Belle Property.

In the first half of 2002, after deciding to move to Europe, The Queen worked for a short period in Paris, where Her Majesty taught English at a Business English School. Later in 2002, The Queen moved to Denmark and was employed by Microsoft Business Solutions as a Project Consultant for business development, communications and marketing.

Military career
The Queen began as a private in the Home Guard in 2008. After training, Her Majesty became a sergeant in the Home Guard 2009, lieutenant in the Home Guard 2009, first lieutenant in the Home Guard 2015, captain in the Home Guard in 2019 and honorary major in the Home Guard in 2023

The Queen has taken part in a large number of activities and exercises under the auspices of the Home Guard through the Army-, Navy- and Air Home Guard.

Language
The Queen's mother tongue is English, and Danish is her second language.

The Crown Princess is patron of many national organisations, institutions, and foundations and is an honorary member of various associations and societies.