Crown Princess Mary of Denmark turns 40 Denmark's Crown Princess Mary is photographed on Feb. 5, 2012, her 40th birthday. Credit: Linda Henriksen (CBS) Crown Princess Mary of Denmark celebrated her 40th birthday on Feb. 5, and the palace has released a new set of pictures to mark the milestone. The Australian-born royal, who married Crown Prince Frederik in 2004, reportedly said she is embracing this "wonderful stage" in her life. Pictures: Crown Prince Frederik and Crown Princess Mary visit Australia I think it is nice to get older. I don't think about my physical age," she told the Danish newspaper Berlingske Tidende, according to Hello! magazine. She added, "At 40 years old you simply know what life is about. I am happy to continue with my journey through time. Frederik and Mary are parents to Prince Christian, 6, Princess Isabella, 4, and 1-year-old twins Prince Vincent and Princess Josephine. The Danish royal family recently celebrated another new addition - Princess Marie and Prince Joachim welcomed their second child, a daughter, on Jan. 24.