The Princess' name is yet to be announced. Photo / AP
The Duke and Duchess of Cambridge are not expected to announce the name of the new princess for at least a couple of days, fuelling a late frenzy of bets.
Prince George's little sister was born at 8.34am UK time yesterday, almost a week overdue. After George was born, officials waited two days before announcing his name.
For the newborn princess punters are favouring Alice, Charlotte or Elizabeth but there are several other popular choices that the Royal couple will be wresting with.
Alexandra is one of the Queen's middle names. The Queen's great-grandmother was Queen Alexandra.
Queen Alexandra, who was born in 1844, was married to King Edward VII. A Danish princess, she was known to her family as Alix. She was once considered one of the most beautiful princesses in Europe. Like William's mother, she held the title the Princess of Wales.
Alice has been a favourite at the bookmakers. Princess Alice was the third child and second daughter of Queen Victoria and the great-grandmother of the Duke of Edinburgh. Her daughter Alix married Tsar Nicholas II of Russia and was later executed alongside her family by the Bolsheviks in 1918.
Her granddaughter, also called Alice, was the Duke of Edinburgh's mother - Princess Alice of Battenberg. She later fell ill and was committed to a sanatorium. In later years she went to live at Buckingham Palace and was said to walk around in a nun's habit, smoking.
William and Kate could name their daughter Charlotte - the feminine form of Charles - in honour of the Duke's father and the baby's grandfather, the Prince of Wales. Queen Charlotte, who was born in 1744, was married to George III. Charlotte was actually her second name - her first was Sophie.
A keen botanist, she founded Kew Gardens, had 15 children and was a patron of the arts. Some historians have argued that she was of African descent. Her daughter, born in 1766, was also called Charlotte.
Charlotte is also the middle name of Kate's sister Pippa Middleton.
William and Kate are also likely to want to remember the Duke's late mother Diana, Princess of Wales, who died in a car crash when William was 15.
The Duke places great importance on honouring her memory, having used Diana's sapphire and diamond engagement ring when he proposed to Kate. It is thought likely they would use the name Diana, if not as a first name then as one of their baby daughter's middle names.
There is speculation William and Kate will pick Elizabeth - if not as a first name then as a middle name - in honour of William's grandmother and the reigning Queen. The Queen is held in great respect by her family, and William has spoken of how she has become an even more important part of his life as he has grown older. Kate, too, has forged a strong bond with William's grandmother. The Queen was known as Lilibet as a child. William's great-grandmother, the Queen Mother, was also an Elizabeth. It is Kate's middle name and her mother's middle name.
Frances was Diana's middle name and the first name of her mother, Frances Shand Kydd.
It is also a recurring name in Kate's family tree. It was her great-great-great grandmother's first name and appears several times in the male form Francis.
Mary is one of the Queen's middle names. It was also her grandmother's name. Mary of Teck married George V.
Britain has seen two Marys on the throne - Mary I, known as Bloody Mary for her persecution of Protestants, and Mary II, who ruled jointly with her Dutch husband William III.
Kate might choose to remember her grandmothers Valerie and Dorothy. Harriet is also a family name on her father's side. She could decide to use her mother's name, Carole or a form of it, such as Caroline or Carolina.