Kate Middleton and Prince William refer to their child as their "little grape"
"Kate and William call it 'our little grape,'" a source said.
"She's got sugar on the brain. Chocolate, biscuits, cake."
Meanwhile, The Duchess of Cambridge said Sunday that she doesn't know the sex of her first child -- but she hopes it's a boy.
Her husband Prince William, however, would prefer a girl.
The former Kate Middleton, who is five months pregnant, made the revelation to a soldier at a St. Patrick's Day ceremony honoring the Irish Guards.
"I asked her `do you know if it's a girl or boy?' and she said `not yet,"' said Guardsman Lee Wheeler.
"She said `I'd like to have a boy and William would like a girl."'