Kate, 32, was certainly animated and engaged Tuesday as she dropped to her knees and chatted with children at an elementary school in North London, where she was checking on a pet project that helps kids from families affected by addiction.
Among the kids she greeted was a little 4-year-old, Ezekiel, who said he made Kate smile when she asked him what his favorite part of school was. "Lunchtime," he quipped. "She laughed. She is pretty."
A little girl, Seyi, 6, told Kate: "I said it was because she has come to Blessed Sacrament school. I said I liked her dress."
Kate, 32, wearing a salmon pink dress by Goat, brought a smile to the flag-waving kids as she viewed the progress of M-PACT Plus, which helps address addiction in families.
Inside the school, she listened intently to teachers and charity workers as she was updated about its success so far. "Were the parents quite surprised by the things their children were saying?" she asked at one point.
She also asked, "Have you found it difficult to attract parents, given the stigma that can be associated with these issues?"
She remarked that the training being given to teachers to spot children who may have issues due to their parents' substance abuse "gives them more confidence to approach the topics."
Kate launched the initiative with comedian John Bishop while on a visit to Manchester in 2013, when she was pregnant with her son, Prince George.
The project is funded by The Royal Foundation of The Duke and Duchess of Cambridge and Prince Harry in conjunction with Comic Relief and two of Kate's charities, Place2Be and Action on Addiction.
Kate is "genuinely committed" to the issues raised by the M-PACT project, Bishop said. He and Kate discussed parenthood and revealed that she told him Prince George, who runs one on July 22, was "racing around." The Duchess was also heard saying, "He's so fast and I can't believe he is opening doors already."
Earlier, Kate had been keen to hear about the "positive outcomes," especially of how the M-PACT pilot had been working to increase "parents' awareness of how substance abuse impacts families," Sarah Kendrick, Place2Be's service manager for Central London, tells PEOPLE.
"She is personally and passionately interested," she said. "I know her passion in her patronage of both organization and that speaks volumes."
Outside, Kate was presented with a portrait of herself and Prince George painted in the style of Picasso. Artist Rosie Nee, 11, had created the work as part of a project.
Barbara Smith chair of the school governors, praised Kate for coming to the school and for highlighting the work of the two charities that work to halt the scourge of addiction. "It's incredible that she has this involvement in an area where a lot of people want to avoid," she says. "It's a dark area."
On Monday, Kate took husband Prince William with her to the annual conference of Place2Be, which provides counseling for children in schools.
The visit was unpublicized and, the palace says, meant to be private. They spent two to three hours at the event in London, listening to speeches and presentations.
Monday's conference looked at the transition years between grade school and high school education, and the importance of providing in-school mental health services at the earliest stage possible to tackle problems before they escalate. "It is an area that both the Duchess and indeed the Duke have a special interest," a source tells PEOPLE.