A lovely reply arrived today from the UK. I had written to Princess Eugenie and Jack Brooksbank for the birth of their son August Brooksbank.
The envelope features the usual postmark from the Court Post office at Buckingham Palace. From the postmark, we can see this was mailed out weeks before Prince Philip's death (in case you were wondering).
Inside is a photo card. The front features a photo of the family. The photo was part of the set released to mark August's birth. The photo was taken by Princess Eugenie's midwife.
The card reads:
Thank you so much for thinking of us and celebrating the birth of our beautiful boy, August.Words can't express the joy and love we feel.
With our very best,Eugenie and Jack.