Prince William and Princess Kate sent a fan the sweetest photo of the Wales children

Prince William and Princess Kate's office sent a royal fan the most thoughtful thank you letter.

Instagram account @theduchessofwonderland shared two photos of the special post they received just recently, with the caption: "The Wales family Christmas reply was a lovely surprise this morning"

The first showed that they were sent the below photo of William, Kate, and their children Prince George, Princess Charlotte, and Prince Louis at Sandringham in Norfolk this past Christmas:

The second was a typed note on Kensington Palace letterhead that read: "Thank you for your thoughtful Christmas message to The Prince and Princess of Wales, Prince George, Princess Charlotte and Prince Louis.

"Their Royal Highnesses are very grateful and send you their best wishes for a very Happy New Year."

The letter was postmarked on 29 March, but we can only imagine how many letters the office tries to reply to, so we'll forgive them that slight (ahem, three-month) delay this time around.

Funnily enough, despite being a letter from Kensington, the postmark came from Buckingham Palace—and featured King Charles' brand new cypher.

Another important detail we've spotted is the fact that the note was marked with the FSC (Forest Stewardship Council) symbol, meaning that it used sustainably sourced paper.

This is especially important coming from Prince William and Princess Kate, since sustainability is one of their dearest causes. The Prince even launched the Earthshot Prize, now in its third year, which awards £1 million each year to a group working to reverse the climate crisis.

The inaugural Earthshot Prize was held in London, and saw celebrities including Emma Watson, Emma Thompson, Mo Salah, Mayor Sadiq Khan and many more attend the green carpet event.

The second Earthshot Prize took place in Boston, Massachusetts in December 2022, with guests including Chloe and Halle Bailey, Rami Malek, Ellie Goulding, Clara Amfo, Shailene Woodley, Mitt Romney, David Beckham and many more in attendance.

Prince William has yet to announce where the Earthshot Prize will take place in 2023.