Britain's Kate, Duchess of Cambridge, right, accompanies Queen Elizabeth II, unseen, and Prince Philip, left, at Baker Street underground station in London for a visit to mark the 150th anniversary of the London Underground, Wednesday, March 20, 2013. (AP Photo/Sang Tan)
Britain's Kate, Duchess of Cambridge, right, accompanies Queen Elizabeth II, unseen, and Prince Philip, left, at Baker Street underground station in London for a visit to mark the 150th anniversary of the London Underground, Wednesday, March 20, 2013. (AP Photo/Sang Tan)