They're not even down the aisle yet, and speculation on when Prince William and Kate Middleton will produce an heir is rampant.

A U.K. newspaper used it as the subject of an April Fool's joke, and last week a U.S. tabloid suggested Middleton is already preggers.

While that's highly unlikely, a Canadian psychic consultant foretells three children will follow in the years after the royal wedding.

"The purpose of their union is to produce heirs," says Tara Greene, a Toronto tarot card reader and astrologer.

"My intuition keeps saying they will have three children - I see two girls and a boy."

The first child will be named Diana after William's mother, while the other daughter will have Rose in her name, predicts Greene, who's a regular media commentator on all things other-wordly.

The family will defy the traditionally stuffy royal parenting style, she adds.