UPDATE, 1/21/12: People.com reports that Prince William will join his in-laws on their getaway once his military schedule allows.
PREVIOUSLY: The Duchess formerly known as Kate Middleton is taking a holiday with her family in the Caribbean.
The family, including Pippa and James, reportedly flew first class on a British Airways flight from London's Gatwick Airport to St. Lucia, a photographer blogged. It's assumed that the family continued on from St. Lucia to their favorite haunt, Mustique. (Also the location of Paul McCartney and Nancy Shevell's honeymoon.)
Clarence House refused to comment on the vacation, even though it's been reported that the Duchess of Cambridge's personal security team is with her. In December, Prince William and Princess Catherine canceled their ski trip due to concerns that they would be seen as lavish during a recession.
When reached for comment by The Huffington Post, a spokeswoman for British Airways said that the airline "never comments on individual passengers due to data protection legislation."