Royal Baby Number 2 Is Here! Duchess Of Cambridge Gives Birth To Her Second Child

Bust open a bottle of Pimm's -- the second royal baby has arrived! Catherine, Duchess of Cambridge, gave birth to a little girl Saturday at St. Mary's Hospital, Kensington Palace confirmed.

Pictures of the new princess emerged on Saturday evening:

Kate, Duchess of Cambridge, looks at her newborn daughter as she stands alongside Britain's Prince William outside St. Mary's Hospital's exclusive Lindo Wing, London, Saturday, May 2, 2015. The Duchess gave birth to the Princess on Saturday morning. (AP Photo/Alastair Grant)

Britain's Prince William carries his newborn daughter as he and Kate, Duchess of Cambridge, leave St. Mary's Hospital's exclusive Lindo Wing, London, Saturday, May 2, 2015. The Duchess gave birth to the Princess on Saturday morning. (AP Photo/Alastair Grant)

Britain's Prince William, right, and Kate, Duchess of Cambridge, pose for the media with their newborn daughter outside St. Mary's Hospital's exclusive Lindo Wing, London, Saturday, May 2, 2015. The Duchess gave birth to the Princess on Saturday morning. (AP Photo/Alastair Grant)

This is the second child for the duchess and Prince William , who welcomed Prince George in July 2013 (to much fanfare ). The palace announced that the couple was expecting back in September, long after media outlets began buzzing that baby number two was on the way months after George 's birth.

Surprisingly, the duke and duchess' second bundle of joy arrived past its due date of April 2015 .

While pregnant with her second child, Kate suffered hyperemesis gravidarum , a severe form of morning sickness, which she experienced during her first pregnancy. The duchess received treatment by doctors at home in Kensington Palace and managed to resume her busy schedule of royal engagements, even making a visit stateside .

The new baby is officially fourth in line to the throne, effectively bumping her uncle, Prince Harry , down to fifth. (Yes, daughters can now ascend the English throne ).

Now that there's an "heir and a spare," Prince George finally has a playmate -- just like his dad had with Prince Harry , who is only two years younger than Will. The new baby and George are even closer in age, just 21 months apart. Judging by Georgie's solo baby photos , one can only imagine how adorable the sibling pics are going to be.

The world has yet to catch the first glimpse of the second royal baby and her mum or even learn the tyke's name , so stay tuned for updates!