She bumped into them during a dinner at the National Portrait Gallery on Tuesday 28 March, where she met artists, trustees and donors in the gallery in London.
“I’m not sure George has any idea what’s going to hit him,” she told them, discussing him starting school, according to The Telegraph.
The Duchess met architect Richard Found and his wife Jane Suitor, an art consultant and collector, whose child goes to the school.
“We were chatting about Thomas’s, the school George will be going to,” Found said after meeting her.
“We’re parents there as well. She just said: ‘I may see you at the school gates.’”
Found told the Duchess Prince George would love the “friendly” school.
The family announced they would be sending Prince George to Thomas’s Battersea School on 24 March.
The school is one of the top in London, and costs £6,110 a term. It’s a mixed prep school for 540 students, and pupils start at age four and finish at 11.
The biggest rule of the school is a wonderful one: “Be kind”.
Headteacher Ben Thomas reportedly wrote a letter informing parents about Prince George’s imminent attendance.
He wrote: “This is clearly a significant moment for their family and most certainly for Thomas’s.
“Like so many parents, the Duke and Duchess have put a great deal of thought into the choice of their eldest child’s first ‘big school’.”