Kate Middleton Had a 'Tight' Circle of Knowledge Around Cancer News: 'Heck of a Shock,' Friend Says (Exclusive)

Wary of leaks to the press, the Princess of Wales was open about her diagnosis to some, but other close friends and confidants were unaware

Always wary of leaks to the press, Kate Middleton had been open about her cancer diagnosis to some, but other close friends and confidants were unaware.

"It was a heck of a shock," one tells PEOPLE exclusively in this week's cover story

Adds a former palace aide: "The circle of knowledge was very tight. "

In a video that sent shockwaves around the globe on March 22, Princess Kate, 42, revealed that she had been diagnosed with cancer and was undergoing chemotherapy. The royal mom, so famous for her unerring poise, spoke about initially keeping the diagnosis private for "the sake of our young family," her voice cracking at the reference to Prince George, 10, Princess Charlotte, 8, and Prince Louis, 5, whom she shares with Prince William.

Against a backdrop of yellow daffodils, often seen as a symbol of hope for those with cancer, Kate managed a hint of a smile as she said, "I am well and getting stronger every day by focusing on the things that will help me heal; in my mind, body and spirits."

"At this time, I am also thinking of all those whose lives have been affected by cancer. For everyone facing this disease, in whatever form, please do not lose faith or hope," she concluded. "You are not alone."

Says a source close to the royal household, "She held it together."

Related: Kate Middleton and Prince William Make a 'Fantastic Team,' Says His Cousin Peter Phillips

Behind the scenes, the Princess of Wales has been taking steps to prioritize her health and well-being, but she hasn’t been in complete seclusion. Both she and Prince William, 41, have been spotted at their children’s sports events and lessons in recent weeks. On March 16, the couple were photographed running errands together at Windsor’s Farm Shop.

"Having fun together when they can is very important," says a family friend. "This is about her feeling supported. She doesn’t feel isolated at all."

Kate’s parents, Carole and Michael Middleton, have been an additional source of help, with Carole accompanying her daughter on school drop-offs. Kate’s younger siblings, Pippa and James, along with their families, are also nearby. In a touching statement accompanied by a photo of himself and Kate as children, James wrote on Instagram: "Over the years, we have climbed many mountains together. As a family we will climb this one with you too."

Related: Kate Middleton’s Own Words Announcing Her Cancer Diagnosis: Read Her Official Statement

While Kate’s health crisis has strengthened the safety net around her, it has also highlighted the royal family’s ongoing estrangement from Prince Harry and Meghan Markle, who learned the news at the same time as the rest of the world. However, they privately reached out to William and Kate following the announcement and publicly released a statement: "We wish health and healing for Kate and the family, and hope they are able to do so privately and in peace."

In the days following Kate’s announcement, she and William resumed focusing on their children, who are currently on their Easter break. The family of five will skip tradition by opting out of the royals’ Easter services at St. George’s Chapel at Windsor Castle and instead spend the long weekend privately at home.

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The Prince of Wales will resume public duties after George, Charlotte and Louis return to Lambrook School on April 17, and Kate, who will remain out of the public eye during her treatment, may join in events when she feels able. But palace sources say that would not necessarily signal a return to royal duties — that decision will rest on doctors’ advice. For now, her focus is on her full recovery, with her family there to support her.

"She has the inner strength, the support of her husband and her extraordinary family, so she can focus on what’s important," says Ailsa Anderson, a former spokeswoman for Queen Elizabeth, "which is her getting back to strength."

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