Britain's Prince William (L) and Catherine, Duchess of Cambridge wave while visiting the Guildhall in Cambridge, central England November 28, 2012. [Photo/Agencies]

"DADDY'S LITTLE CO-PILOT"

Kate made her last public appearance on Friday when she returned to her old school - a minor event that nonetheless generated live television coverage on news channels - when she looked healthy and joined in a game of hockey with pupils.

Earlier in the week William had hinted at a pregnancy during a visit to Cambridge in central England when they were given a home-made baby suit emblazoned with the words "Daddy's little co-pilot", a reference to William's job.

"When I gave it to him he said 'I'll keep that', and handed it to his aide," said Samantha Hill.

Joseph, author of "Kate: The Making of a Princess", said she believed the couple, who currently live in north Wales where the prince is based as a search and rescue pilot, had been waiting for the right moment to have a baby.

"My feeling has always been that they were not going to take the spotlight away from the queen in her Jubilee. But now 2013 is going to be William and Kate's year," she said, adding the couple would make wonderful parents.

"We have seen her with children and she is lovely with them, she's got the natural touch, and her parents run a party business and she has spent a lot of time with children," Joseph said. "(William) he has always talked about wanting children, so I am sure he is delighted."

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