Through marriage.  She married King Willem-Alexander in 2013, making her "Queen consort."  From Wikipedia...  Queen Máxima of the Netherlands (born Máxima Zorreguieta Cerruti;[1] 17 May 1971) is the wife of King Willem-Alexander. On 30 April 2013, she became the first queen consort of the Netherlands since Emma of Waldeck and Pyrmont (queen consort from 1879 to 1890) and the first Latin American-born queen consort in the history of the Netherlands.   https://en.wikipedia.org/wiki/Queen_M%C3%A1xima_of_the_Netherlands