July 10 (UPI) -- Harper Beckham celebrated her sixth birthday at a princess-themed party at Buckingham Palace.
"Our little birthday princess x Kisses," Victoria captioned a photo on Instagram of her daughter in a Cinderella dress.
David shared a series of pictures on his own account, including a snapshot of himself embracing Harper outside the palace and a photo of his daughter and her friends meeting Princess Eugenie, a niece of Prince Charles.
"Happy Birthday to our special little young lady," David wrote. "Such a special girl who brings so much joy and happiness into our lives.. Happy 6th birthday (I can't believe your 6 already) have the most amazing day we love you pretty lady x."
David and Victoria also rang in Harper's birthday at a low-key party with their extended families Saturday. The 42-year-old retired soccer star and 43-year-old designer and former Spice Girls singer celebrated their 18th wedding anniversary last week.
"Wow we really did this," David wrote July 4. "Happy Anniversary to an amazing wife, mummy and strong business woman. Love you x."
David and Victoria are also parents to three sons, 18-year-old Brooklyn, 14-year-old Romeo and 12-year-old Cruz. The designer was named an OBE, or Officer of the Most Excellent Order of the British Empire, by Prince William in April.