Prince William, the Duchess of Cambridge (in Catherine Walker & Co.), Prince George and Princess Charlotte

ROYAL BABY: Kensington Palace has confirmed that the Duke and Duchess of Cambridge are expecting their third child.

The expectant child will be sibling to Prince George, who turned four in July, and Charlotte, who celebrated her second birthday in May, and the news comes as the Duke and Duchess are preparing to send Prince George to school for the first time.

As with previous pregnancies, the duchess is suffering from severe morning sickness and as a result had to cancel engagements planned for today.

“The Queen and members of both families are delighted with the news,” the statement said. “As with her previous two pregnancies, the Duchess is suffering from hyperemesis gravidarum. Her royal highness will no longer carry out her planned engagement at the Hornsey Road Children’s Centre in London today. The Duchess is being cared for at Kensington Palace.”

This will be the Queen’s sixth great-grandchild and the fifth Royal family member in line to the throne, following Prince Charles, Prince William, Prince George and Princess Charlotte.

During the earlier stages of her pregnancy, the Duchess attended a tour of Kensington Palace’s White Garden, to mark the anniversary of the death of Princess Diana, in a loose floral dress. In July, she also undertook a tour of Poland and Germany, participating in a rowing race and hinting at her third pregnancy when she was presented with a toy designed for newborns.