Kate started the tradition of sharing official portraits of her little ones with her and the Duke of Cambridge's eldest son Prince George, now five.
The day before Charlotte's second birthday in 2017, Kensington Palace released a stunningly beautiful new photo and thanked royal well wishers for their messages of support.
In a statement to E! News, a spokesman for the Duke and Duchess said: "Their Royal Highnesses would like to thank everyone for all of the lovely messages they have received, and hope that everyone enjoys this photograph of Princess Charlotte as much as they do."
Last year, Charlotte's great-grandmother Queen Elizabeth arrived at Kensington Palace by helicopter to wish her a happy third birthday and also to meet her newest grandson Prince Louis.
The Palace released a sweet photo of Charlotte on the steps of Anmer Hall, and four days later shared another shot with her newborn baby brother taken on the Princess' birthday.
The Queen brought a bunch of hand-picked flowers, said to be a gift for Kate after giving birth.
The Duchess of Cambridge famously gave the monarch a jar of her homemade chutney for her first Christmas with the royal family.
Whether this year's birthday photos will include George and Louis or simply Princess Charlotte on her own remains to be seen.
Princess Charlotte's birthday could easily become one of the most celebrated days of the year for the royal family if the heavily pregnant Duchess of Sussex gives birth to her first child on May 2.
Baby Sussex, seventh in line to the British throne, will be the fourth grandchild for Prince Charles and the late Princess Diana.