The Prince of Wales disclosed his preference as he chatted to veterans while at Windsor Castle to present new Colours to the 1st Battalion Welsh Guards, which is celebrating its centenary year.
Lynda Bateman, whose 100-year-old father, Eric Jones, is the oldest surviving member of the Welsh Guards, said: "My father introduced me as his daughter and Prince Charles asked how many daughters he had.
"My father said 'One - and that's enough' and Charles laughed and said 'And we're hoping for a granddaughter!"'
Charles was at the event with Camilla, and was joined at Windsor Castle by the Queen and Duke of Edinburgh. When asked if she had any news about the baby, Camilla said: "No."
Royal superfans have been camping outside of Lindo Wing, and yesterday, parking restrictions outside St Mary's Hospital were extended into May. According to reports, Kate is around four days overdue.
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Kate Middleton's maternity wardrobe!