Royal baby No. 3 on the way for William, Kate

Prince William and his wife, the Duchess of Cambridge, will soon welcome a third child to the royal nursery.

Prince William and his wife, the Duchess of Cambridge, will soon welcome a third child to the royal nursery.

Kensington Palace officials announced Monday that the former Kate Middleton is pregnant, but was not feeling well enough to attend an engagement later in the day.

As with her other two pregnancies, she is suffering from hyperemesis gravidarum, or acute morning sickness.

She is being cared for at the royal couple’s apartment in London’s Kensington Palace.

The sickness failed to dampen the buoyant mood among the royals, however. Prince Harry will be bumped down in the line of succession, but was overjoyed, describing the news as “fantastic,” and offering a thumb’s up while on a visit to Manchester.

And asked how the Duchess was he said: “I haven’t seen her for a while but I think she’s OK.”

No details were immediately available about when the third baby is due, though the duchess is less than 12 weeks pregnant. That would put the due date somewhere between mid-March and mid-June.

William and Kate, both 35, already have two children: Prince George, 4, and Princess Charlotte, 2.

The announcement comes as the royal couple prepared to mark another milestone for their young family: Prince George is scheduled to start school Thursday at Thomas’s Battersea in south London.

Their choice of a south London school indicated that the royal couple was settling into their Kensington Palace apartment, having moved recently from their Norfolk home, Anmer Hall.

Betting agencies were

quick to start offering odds on possible names for the soon-to-be addition to the House of Windsor.

Paddy Power offered 8-to-1 odds on Alice and 10to-1 odds on Arthur. Also popular is Diana, after Prince William’s mother,

particularly given the timing of the announcement.

William and Kate took a leading role in marking the 20th anniversary of Diana’s death last week.

The couple, joined by Prince Harry, toured the garden of Kensington Palace

to commemorate the princess’s contributions to their family and the many charities she supported.

“Given the recent anniversary, there’ll be plenty of interest in the name Diana if the baby is a girl,” Paddy Power said.

KIRSTY WIGGLESWORTH — THE ASSOCIATED PRESS FILE Britain’s Kate, The Duchess of Cambridge, Prince William and their children Princess Charlotte and Prince George appear on the balcony of Buckingham Palace, after attending the annual Trooping the Colour Ceremony in London. Kensington Palace says...