Britain's Catherine, Duchess of Cambridge, presents shamrock flowers at a parade ground at Aldershot army base in southern England March 17, 2012. She was presenting shamrocks to members of the 1st Battalion Irish Guards, a tradition on St Patrick's Day.[Photo/Agencies]

Britain's Catherine, Duchess of Cambridge smiles as she leaves after her visit to the Rose Hill Primary School in Oxford, southern England February 21, 2012. The Duchess who is patron of the charity The Art Room, visited two schools in Oxford on Tuesday.[Photo/Agencies]

Britain's Prince Charles and Catherine, Duchess of Cambridge leave after their visit to the Dulwich Picture Gallery in London March 15, 2012.[Photo/Agencies]