This is an example of a letter sent by Princess Máxima. Note that members of the Dutch Royal House rarely write a letter by themselves. They have a professional Secretary with dozens of people working for them. The picture shows a copy-of-a-copy, so the Arms (which is printed in relief on the original paper and does not copy well) is not visible.
Picture:
http://www.anneliesvanderham.nl/briefmaxima.jpg
Translation:
Most Esteemed Mrs,
On request of Her Royal Highness Princess Máxima of the Netherlands I hereby express a most heartfelt gratitude for the beautiful dolls' house "Het Kleine Loo" that You have handed to her last november 23rd.
Princess Máxima and her daughters are most pleased with this showpiece, which will be carefully preserved for many generations to come. The Princess would like, via Your intervention, to thank all people whom have spend so much time in the creation of this dolls' house. She has a lot of appreciation for the craftmanship and dedication which has been shown by all.
On behalf of Princess Máxima I wish You all the best for Your personal wellbeing.
With feelings of the most high esteem,
[signed]
Mrs Y. van Eechoud LL.M.
Deputy private secretary of His Royal Highness The Prince of Orange and Her Royal Highness Princess Máxima of the Netherlands