And smiley Kate who was just nine-years-old proved she had the ability to perform the famous Royal wave with ease.
The adorable photos from a 1991 wedding video show both sisters dressed in satin wedding dresses looking every inch the quintessential English roses.
And they prove the well-behaved sisters who were performing bridesmaid duties for their Uncle Gary Goldsmith enjoyed being part of the formal ceremony.
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Duchess Kate looked pretty alongside sister Pippa in this 1991 video
The 26-year-old video is a throwback to the early 90s and shows the girls in peach pastel hues with white flower garlands in their hair.
Indeed the hair decorations were startlingly similar to the Duchess of Cambridge's own wedding where bridesmaids wore similar bands by Floral artist Shane Connolly.
The photos show Catherine and Pippa in various poses and there's an adorable shot of their younger brother James, who was just four struggling to cope with his top hat and tails.
Catherine's younger brother James was just four years old
The photos were taken from a wedding video outside St Peter's Church in Burnham, Buckinghamshire when Kate's then 26-year-old uncle Gary Goldsmith married his first wife Maria Foote.
Unfortunately the couple are reported to have split up just 18 months later with Gary then going on to marry for a fourth time.
The new photos emerged just a few months before Kate's sister Pippa plans to walk down the aisle herself.
Katie's Uncle Gary has now been married four times
The writer and children's party organiser is planning on marrying her hedge fund fiance James Matthews in May of this year.
It has been reported that Prince George and Princess Charlotte will haves roles as page boy and flower girl during the anticipated nuptials.
Catherine and Pippa looked very well behaved at Uncle Gary's wedding
Catherine, Duchess of Cambridge looks pensive in some of the images
Little Pippa will soon be getting married herself after her engagement last year