Prince George has a passion for aeroplanes and could even be set to join the air cadets when he grows up.
She was speaking to Lucinda Conder, 19, who won top female cadet of 2015, at her first engagement as Honorary Air Commandant.
The Duchess said the obsession could have stemmed from having previously shown George pictures of Spitfires after a royal engagement.
Ms Conder said she was told, according to PA: "[George] is now obsessed with the air cadets and wants to join.
"We are going to have to push that one when he gets to 12."
But it'll be a while before the toddler joins, seeing as he's only just started attending nursery.
The Duke and Duchess of Cambridge released two adorable photos to mark George's first day at Westacre Montessori School nursery in Norfolk back in January 2016.
The Duke and Duchess have released 2 photos to mark Prince George's first day at Westacre Montessori School nursery pic.twitter.com/a5ScewaRJ4— Kensington Palace (@KensingtonRoyal) January 6, 2016
Prince George arrives for his first day at nursery in Norfolk earlier today pic.twitter.com/w4BPGNE1H0— Kensington Palace (@KensingtonRoyal) January 6, 2016