The card featured a crepe paper floral arrangement in a yellow paper vase with a heart, which was positioned on top of a colourful checkered background.
In addition to George’s handiwork, the Duchess also shared a previously unseen throwback snap of her children, along with pics of herself, Wills and Harry as children.
According to Express, Kate and Wills’ two eldest children will be taking time away from Thomas’s School in Battersea, as the school introduces “remote learning”.
The school has reportedly implemented distance learning as a precautionary measure, with no one at the school – staff or pupil – testing positive for the virus.
Thomas’s has four schools, in Battersea, Clapham, Kensington and Fulham, and while several students are believed to have been tested, no one has received a positive result for COVID-19.
A spokesman for Thomas's schools said: "Due to the increasing numbers of children and staff being absent from school due to the coronavirus situation, Thomas's London Day Schools have decided to move to remote learning from Friday 20 March.
"From this date the curriculum will be taught through online learning platforms and we have asked parents to keep their children at home and to access their lessons through this system.
"This will ensure that children have continuity of learning when they are unable to attend school,” the statement read.