Domenica Lawson is the inspiration behind a new charity to help young adults with learning disabilities
Credit: Andrew Hasson

When Rosa Monckton welcomed daughter Domenica —

who was born with Down syndrome — in 1995, it was her close friend Princess Diana who provided the ultimate support.

“She said, ‘You just have to believe in her,’ ” Monckton tells PEOPLE in this week’s issue of Diana, who was Domenica’s godmother.

“She said, ‘Believe in her, love her and I’ll be there every step of the way,’ ” recalls the British jewelry executive, 62, who met Diana through a mutual friend. “She already had that vision of what Domenica could become, which I simply couldn’t see.”

Now thriving at 21, Domenica is fulfilling that vision — and she is the inspiration behind Team Domenica, a new charity set up by her mother to help young adults with learning disabilities gain experience to break into the workplace.

The princess, who died when Domenica was two years old in 1997, “was a huge encouragement,” after Domenica’s birth, says Monckton. “She came with me to appointments. She was very much by my side.”

And it was Diana who told her friend about Chicken Shed, the performing arts theater company in north London, saying it would be perfect for her. Domenica attended for more than three years.

“She’s always going to be vulnerable, she’s never going to be able to live on her own,” says Monckton of her younger daughter. “Each step of the way is a battle, frankly for all parents.”

Domenica works at the café set up by Team Domenica in Brighton, England, where she and her peers also receive continuing education. She was center stage when actress Julie Walters cut the ribbon to open the charity in early September. (Walters is her favorite star from her most loved movie, Mamma Mia.)

“We talked about Mamma Mia and Paddington,” Domenica says of that evening. “She said that it was funny making it. I felt really special that she was here.”

As for Diana, says Monckton, “She would be so proud of Domenica and what she’s achieved and of this.”

Credit: Courtesy Rosa Monckton

Eventually Monckton hopes to branch out and take her charity to other cities and around the U.K. She has raised $730,000 and needs $370,000 a year to to expand. “I can’t think of anything that is needed more to protect and look after this incredibly vulnerable group of people,” she says.

With the charity focused on teaching key life skills and through partnerships with local businesses, Monckton aims to help participants land a job, “even if it’s a few hours a week,” she says. “If someone believes in you, then you believe in yourself.” With the charity only a month old, six young people already have been lined up for placements in November.

On Wednesday, cooking guru Nigella Lawson (she’s the sister of Domenica’s dad, journalist Dominic) is bringing her own expertise to the café, teaching the participants how to make a special new treat: Team Domenica cupcakes.