George's father William has a fondness for riding bikes which, she said always fills her with "horror".
"He's still riding it. It always fills me with horror when he goes out on it. I'm terrified. Hopefully, I'm going to keep George off it," she said when asked by a recruitment executive from Ayr if the Duke was still riding his Ducati motorbike.
The Duchess of Cambridge was touring Dundee in Scotland in support of a festival which is challenging preconceived ideas about mental health.
William and Kate, together with Prince Harry, are making the emotional and psychological wellbeing of young people a key focus of their official and charitable work.
The royal couple were regular visitors to Dundee when they were students at St Andrews in Scotland.
"I have very fond memories of coming to Dundee when I was a student," Kate told a group of Dundee University students.
