She is prohibited from being paid for her work
Some may find this a somewhat odd rule for the modern world, but Kate is not allowed to profit from her work. Kate is an avid photographer and has posted professional photos that she has taken over the years. One could only imagine the fortune she could have amassed from all her work over these years, after coming into the spotlight. But, that is something Kate is prevented from doing. As frustrating as it sounds, she is not allowed to make money, yes, you read that right!
Under normal circumstances, she could license her photos for profit. And that would make complete sense, given that the world is dying to see pictures of the royal family. However, as she is a member of the royal family, her work is made public by the palace and she does not personally benefit from it. There is no profit or loss she incurs from her work. Every picture she shares with the world, has to be approved and then released by the palace. Her only job would be to serve the Queen and in return she can live the life she lives with her husband, Prince William. As much as she would have loved to, she doesn’t really have a salary for all the official engagements.