The image shows the Duchess rocking a party hat and blowing on a party popper alongside her younger sisters Pippa and James.
"It is still very much a family business today, and over the years all my children have played a huge part in it from modelling for the catalogue to developing new categories for the brand," Carole writes.
Party Pieces was born in 1987 while Carole was pregnant with James and Kate was due to start school. The idea came from “being a mum who was new to hosting children's parties, finding the simplest of things like party bags was a real challenge.”
The business went from humble beginnings in the Middleton’s garden shed to become a thriving business with over 40 employees – including all three children through the years.
“James established our personalised cakes, Catherine started the 1st birthday side of the business, and Pippa developed the Party Pieces blog.”
While the kids are no longer involved in this business, the proud mum says she still gets their input.
“They grew up with me working and appreciate the demands of a busy business and a working mum, and although now they are not involved day to day in the business, I still value their ideas and opinions.”