Kate Middleton, Duchess of Cambridge, gives birth to baby girl

May 2: Britain's Prince William and his wife Catherine, Duchess of Cambridge, appear with their baby daughter outside the Lindo Wing of St Mary's Hospital. (Reuters)

May 2: Britain's Catherine, Duchess of Cambridge, holds her baby daughter outside the Lindo Wing of St Mary's Hospital. (Reuters)

May 2: Britain's Prince William and his wife Catherine, Duchess of Cambridge, appear with their baby daughter. (Reuters)

May 2: Britain's Prince William and his son Prince George wave as they return to St. Mary's Hospital. (AP)

May 2: An easel is placed in the forecourt of Buckingham Palace in London to announce the birth of the royal baby. (AP)

May 2: Tony Appleton, a town crier, announces the birth of the royal baby outside the Lindo Wing, St. Mary's Hospital, London. (Daniel Leal-Olivas/PA via AP)

May 2: Members of the media surround royal fans and well wishers after Kensington Palace announced that Kate, the Duchess of Cambridge, had given birth to a girl, outside the Lindo Wing of St. Mary's Hospital, London. (Daniel Leal-Olivas/PA via AP)

April 27: Royal fan John Loughrey, aged 60, pulls an an expression and lifts his legs in the air in reaction to media cameras pointing at him as he lies on a camping bed with a baby dummy in his mouth with his Union flag designed outfit across the street from the Lindo Wing of St Mary's Hospital in London. (AP)

May 2: Betting odds are written on a chalkboard outside the Lindo Wing at St. Mary's Hospital in anticipation of Kate, Duchess Cambridge giving birth to her second child. (AP)

July 5: Kate, Duchess of Cambridge and Prince William watch the podium ceremony of the first stage of the Tour de France cycling race in Harrogate, England.  (AP Photo/Laurent Cipriani, File)

March 27: Britain's Prince William and Kate Duchess of Cambridge attend an event in London.  (AP Photo/Alastair Grant , File)

July 2: Britain's Catherine, Duchess of Cambridge, carries her son Prince George alongside her husband Prince William as they visit the Sensational Butterflies exhibition at the Natural History Museum in London. (REUTERS/John Stillwell/Pool)

May 2: Royal fans and well wishers react after Kensington Palace announced that Kate, the Duchess of Cambridge, had given birth to a girl, outside the Lindo Wing of St. Mary's Hospital, London. (Daniel Leal-Olivas/PA via AP)

May 2: People queue outside Buckingham Palace to view an easel with a notice announcing the birth of the new royal baby, in London. (AP)

May 2: A wellwisher holds champagne to celebrate the birth of the royal baby, outside the Lindo Wing, St. Mary's Hospital, London. (AP)

May 2: Crowds gather as Tony Appleton, a town crier, announces to the assembled media the birth of the royal baby, outside St. Mary's Hospital. (AP)