Kate Middleton 'Can Trust' Sister Pippa ‘With Anything She Needs' as Princess Battles Cancer: 'That’s Given Her a Great Deal of Comfort'

As Kate Middleton bravely battles cancer, she has one person she can count on: her sister, Pippa Middleton.

“Pippa is not only Kate’s younger sister, but she’s her best friend and loyal to the bone,” an insider revealed. “Kate can trust Pippa with anything she needs to get off her chest. That’s given her a great deal of comfort. Their bond will see Kate through her recovery.”

“Kate and Pippa were quite the social butterflies,” noted the insider. "They’d go clubbing together and get home late, sleep in when they could, then laugh at their nightly escapades over breakfast.”

Even though Kate, 42, joined the royal family, her sister remains one of her closest allies. “She trusts Pippa with her secrets and vice versa,” said the insider. “They speak all the time.”

“Kate has a difficult time trusting anyone who isn’t family,” the source added. “This became especially true after she married William and became a member of the royal family.”

Kate finally told the world about her cancer diagnosis on March 22 after rumors swirled about her whereabouts.

"I wanted to take this opportunity to say thank you personally for all the wonderful messages of support and understanding whilst I've been recovering from surgery," Kate began. "It has been an incredibly tough couple of months for our entire family. In January, I underwent major abdominal surgery in London. At the time, it was thought that my condition was non-cancerous. The surgery was successful, however, tests after the operation found cancer had been present. My medical team therefore advised I should undergo preventive chemotherapy, and I am now in the early stages of that treatment."

The Princess of Wales continued: "This of course comes as a huge shock, and William and I have been doing everything we can to process and manage this for our young family. It has taken my time for me to recover from my surgery. Most importantly, it has taken us time to explain to George, Charlotte and Louis and to reassure them I am going to be OK. As I've said to them, I am well. Having William by my side is a great source of comfort, and the love and support and kindness that has been shown from so many of you. As a family, we need some time, space and privacy while I complete my treatment. My work has always brought me a deep sense of joy. I must focus on making a full recovery. At this time, I am also thinking of those whose lives have been affected by cancer. Please do not lose faith or hope. You are not alone."

Now, it seems like Kate is leaning on her family during this time.

"This is about supporting her and her feeling supported. It is a joint effort," another insider added. "She doesn’t feel isolated at all. The nuclear family that they have created so well is an immense support not only to him but to Catherine too."

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