She has added three new chapters to ‘Brutally Honest’, which looked back on her childhood, rise to fame and marriage to her ex, who she said had been abusive towards her
The ceremony for Charlotte, who was born last month, will take place on July 5 at St Mary Magdalene Church in Sandringham where William and Kate, known officially as the Duke and Duchess of Cambridge, have a country home on Queen Elizabeth's estate in eastern England.
It will be conducted by Archbishop Justin Welby, the spiritual head of the Anglican Church, who also oversaw the christening of her elder brother Prince George, who will celebrate his second birthday next month.
The newest member of the British royal family, whose full name is Charlotte Elizabeth Diana, in a nod to her late grandmother Princess Diana and her great-grandmother Queen Elizabeth, has not been seen in public since she left hospital with her parents on May 2.