She finished the autumn-ready look with a khaki jacket and matching sweater.
Kate Middleton made her first solo royal appearance on Tuesday, after stepping back from the limelight over the past few months following the birth of her and Prince William's third child, Prince Louis, in April.
In 2004, Kate was spotted wearing the same boots while modelling for the United Kingdom clothing brand "Really Wild Clothing" during the Game Fair event at Blenheim Palace.
The wife of Prince William visited a forest school and garden to see the work being done to give children from urban London the chance to learn about the natural world.More news: Here are the 9 best new features and upgrades
Kate's visit to the school was to see the "Positive impact that the Forest School has on children's emotional and physical wellbeing, " according to Kensington Palace.
During the event, Kate revealed a sweet activity that she enjoys partaking in with her two eldest children, George and Charlotte - spider hunting.
The students told her they were looking for bugs and counting their legs.
It looks like Catherine's visit to the school will be the first of many royal engagements.
Another week, another Duchess closes a auto door.
Kate Middleton made her first post-maternity leave appearance today, and she did so pulling off casual in a way only Kate Middleton can. She also attended Trooping the Colour in June alongside Queen Elizabeth. "Hello, what are you doing here?" she asked one small group of kids.