It read: “The Duke and Duchess of Cambridge have asked me to thank you for your letter, in which you invite Prince George to your 6th Birthday party. I am sorry that it took so long to reply.
“Their Royal Highnesses were extremely grateful for your kind invitation. Having given careful consideration to the possibilities, however, I very much regret that Their Royal Highnesses reluctantly feel they have to decline.
Kate, Duchess of Cambridge, was discovered chatting to a young child in a train corridor as she travelled to the Commonwealth Games without armed guards, a former Commonwealth medal winner has said.
The man in question said he was “stopped in my tracks” as he realised his son had been speaking to the Duchess of Cambridge.
“Nevertheless, I hope that you enjoyed your birthday.”
The letter continued: “The Duke and Duchess of Cambridge were immensely touched that you should take the trouble to write as you did to their son, Prince George.
“It really was most thoughtful of you and Their Royal Highnesses have asked me to send you their warmest thanks and best wishes.”
The woman who shared the heartfelt letter said it was “amazing” and something for her daughter to “keep” for years to come.
Prince George recently celebrated his ninth birthday party, with the young royal said to have enjoyed his day with family and friends.
Source: EXPRESS CO UK