Their first year of marriage has been largely free of controversy.
"The first year of marriage is difficult for everybody and they've adapted to their role admirably," said Ingrid Seward, editor-in-chief of Majesty magazine.
On Thursday, the royal couple visited the London headquarters of the MI6 intelligence agency and also attended a reception.
Royal-watcher tongues have been wagging after Duchess of Cambridge was seen doting over a newborn baby at a charity event. The infant is the son of a British explorer.
William later cradled the baby boy as well. But he brushed off suggestions that he and Kate were getting in a little practice for parenthood.
The Associated Press contributed to this report.