Arianna Clarke had written to Ms Markle telling her that she was an inspiration and invited the Duchess to attend her 10th birthday party.The Huntingdon Primary School student said she was shocked when she received a letter in the post from the office of the Duke and Duchess of Sussex. Arianna said: "I couldn't believe it when I received a letter from Meghan. I had written to her congratulating her on the birth of Archie, and telling her that I think she is an inspiration. "I really like her as I think she represents mixed race people, like me, and shows that you can do anything if you want to. I also invited her to my birthday party on September 1, but she wrote back and said she couldn't make it." Arianna, had a birthday party at Claire's Accessories in Huntingdon, but said one of the best presents she received this year was the letter. "I am going to keep it forever, she's my inspiration," she said. The letter, which was sent by Claudia Spens, the head of general correspondence at the office of the Duke and Duchess of Sussex, read: "It was so kind of you to take the trouble to write as you did and the Duchess of Sussex was touched by your generous words of support. Although I regret it was not possible for her royal highness and her family to join you for tea, or attend your birthday party, the Duchess greatly appreciated your lovely invitation. "Her royal highness has asked me to send you her best wishes and her warmest thanks for your messages of congratulations following the birth of Archie Mountbatten-Windsor. A small thank you for your thoughtful letter I am enclosing a photograph which I do hope you enjoy." Meghan and Prince Harry are currently embarked on a tour of South Africa, where they have met women and children at a special centre in Nyanga township as part of a programme of events.