London, July 11 (IANS) Harper Beckham, the six-year-old daughter of star couple David and Victoria Beckham, attended a tea party with Princess Eugenie and a few friends at Buckingham Palace.The party was organised by the Duchess of York.Harper's parents showed off some images of the special day on social media, as they wished her a happy birthday on Monday, reports dailymail.co.uk.Harper was invited with her friends to attend the extra special tea party which was held in a small drawing room last week. The little girl stood in the grounds of the palace holding a balloon for one photo.She wore a blue fairytale gown to mimic Elsa from "Frozen" for the special day.Victoria shared the image, writing: "Our little birthday princess."She posed with her friends and Princess Eugenie, with David posting the image to Instagram.He wrote: "Lucky Harper, meeting a real-life princess at the Palace."Harper's brother Cruz, 12, wrote: "Dear Harper, I can't believe it has been already 6 years. You are such a big girl so to the best sister in the world. I love you so much. Have a amazing day."Her eldest brother Brooklyn, 18, shared the photo, wishing her a happy birthday.While Romeo, 14, shared another photo, writing: "Happy birthday to the best sister in the world! I hope you have an amazing day. I love you so much."It's not the first time the Beckhams have been at the palace.Victoria received an OBE for her contribution to fashion from the Duke of Cambridge back in April. Former England captain David Beckham was granted the same title for his services to football.