NEW YORK (CBSNewYork) — The royal family is about to get bigger.

Prince William and the Duchess of Cambridge, the former Kate Middleton, are expecting their third child, Kensington Palace announced.

The surprise announcement comes as Kate was forced to cancel public appearances Monday.

The palace said she suffers from a severe morning sickness like her previous two pregnancies.

William and Kate have two other children, Prince George who is 4 and 2-year-old Princess Charlotte.