Not 100% on topic, but...
...it does involve a letter to the Palace.
Once, as a travel agent, I was arranging a London trip for a local family, including a 2 year old child. When the doting grandmother came in to pick up her documents, she informed me that she had written a letter to then 2-year-old Prince William.
Her voice took on a cloyingly sweet tone as she described the letter: "and, William, you and I are the same age, and I won't have any playmates in London, and I'll bet we would have a lot of fun playing together, etc...". The gran was quite optimistic, even certain, that she would receive a letter inviting her and her grandson to tea at KP.
After she left the shop, we all burst into laughter. When she returned from her trip, I could hardly wait to ask her how it turned out. Amazingly, she was NOT invited to tea!