She talked to students who were 4 and 5 years old about feelings and growing up in a safe place.
The kids held their favourite stuffed animals as they watched a claymation movie from her new ad for early years.
Kate asked the group what they thought about the short video, swimming, birthday cakes, and ice cream.
On Monday, Kate gave a speech at BAFTA that was a big step for the Shaping Us campaign.
On Tuesday in Leeds, she set up an Instagram page for The Royal Foundation Centre for Early Childhood.