According to Express.co.uk, a Sunday Express article at the time reported that Kate had told her friends to stop calling her 'Kate' and to use her full name 'Catherine' instead.
“With Prince William’s engagement now a surefire certainty (even Ladbrokes has stopped taking bets on whether it will happen after a flurry of well-placed wagers) there are intriguing signs that Kate Middleton is preparing for her future role," columnist Adam Helliker reported in the article.
“It looks like she’s taking it very seriously indeed too.
“I hear that in the past few weeks the former accessories buyer has quietly informed friends that she would like to drop the informal ‘Kate’ and in future wishes to be known by her full name: 'Catherine'.”
The then 26-year-old's request was made via email and according to the article, her friends were shocked.
One commented that Kate must have suddenly realised that, if things carried on as they were, she will become Queen one day.
They told the reporter: “Everyone knows it’s about to happen with Kate and William, but we were a little surprised about the request to call her Catherine.
“There is a distinct feeling she has started to become very aware of her position.”
Prince William finally popped the question in 2010, and the couple were married on April 29, 2011.
The Duke and Duchess of Cambridge have since had three children, Prince George, 6, Princess Charlotte, 4, and Prince Louis, 1.