Princess Kate play with kid

For any parent who's been in a group sing-along of "Row, Row, Row Your Boat" or "Twinkle Twinkle Little Star," complete with hand actions, it was a familiar scene. Except for one thing.

At the heart of the group, singing along amid all the other moms cradling their children, was a very special guest – Princess Kate.

Wearing a plastic beaded bracelet made by one youngster on her right wrist, and high-fiving a little 2-year-old girl as she sat down, Kate, 33, beamed with happiness when she visited Cape Hill Children's Centre in Smethwick, England, on Wednesday

The children come to the center to learn social skills while their parents were given access to experts or left to simply socialize on their own.

But the joyful scene – Prince George "would have loved this," Kate told the parents – was in stark contrast to the stories about bereavement, depression and severe illness that Kate had heard earlier.

Those talks focused on the challenges facing women, and the effect they can have on children.

Princess Kate with kid

While there will always be a fascination with Kate's clothing, hair, motherhood with George and her baby due in April, we are now seeing a royal with a growing and clear set of public commitments.

The hospice movement, which she was also supporting Wednesday, remains close to Kate's heart. She has given three of her rare speeches on the subject, and she visits centers at home and abroad.

But the area of vulnerable kids and the family circumstances that can lead to those difficulties has become the focus of a period of committed work by Kate.

She has made a series of visits at various charities as she hopes to learn more about the issues affecting children and their families. She even recorded a PSA to kick off Children's Mental Health Week on Monday.

And her work has triggered increased interest. Place2Be, an organization focused on providing in-school mental health support for young people, reports that Kate's PSA has already garnered more than 300,000 views and it has brought about a surge of inquiries.

Princess Kate

"This shows what concern there is from parents to be able to spot the signs and talk openly – to help stop children's emotional worries turning into more serious mental health issues,"

The rise in inquiries is both heartening and worrying at the same time, insiders say. "It's about breaking the stigma associated with coming forward," a palace source says – so it's encouraging that more people are coming forward.

"She's having an impact. She's making a very strong emphasis on early intervention," Sir Tony Hawkhead, the chief executive of Action for Children, tells PEOPLE. "We now know there are growing challenges around mental health both for children and parents, and there's a lot of work to do."

As the princess tries to learn more about the issues, she's finding that the best way is to meet people facing challenges and hear from experts about what can be done.

Watching her at work Wednesday, Hawkhead observed a bright woman, ready to listen. "Before the duchess came, [one woman] was petrified, but when she saw the very warm way that the duchess talked to the first mum she spoke to, she saw she was relaxed. She created an atmosphere of safety and nurture," he says.

Princess Kate with childrens

"She asks great questions. She listens very, very carefully to people talking about themselves and then asks questions that flow from the answers she gets. She makes people feel they're really being listened to and that their story's interesting. There's no fakery."

Hawkhead says she was "certainly affected by one of the stories. She's a young mum, expecting a baby, and there were some moving stories there … She certainly made reference to the fact that they'd moved her a great deal. She said, 'You've brought a tear to my eye.' "

One woman told Kate how she'd lost her partner, which "knocked her sideways," while another had suffered severe depression and wasn't able to leave the house – "and here she was today talking to one of the most famous women on the planet," Hawkhead said.

He's certain Kate will have a lasting impression. "Everything she talked about was focusing on how children achieve their potential and the work that helps people come back to much better places," he said.
 

"You can see she's going to have a keen long-term interest in how children and families and their problems can be tackled."

Princess Kate with family