As
Kate Middleton faces a frightening health battle following her
cancer diagnosis , the Princess of Wales has turned to her family for love and support. Royal expert Katie Nicholl spoke with ET's Nischelle Turner in
London about Middleton leaning on her parents -- Carole and Michael Middleton -- after she revealed on Friday that she had been diagnosed with cancer in an emotional video message. "She has a really tight group of
Friends and, particularly in Norfolk, really close friends there. But I think the real anchors in her life are her parents," Nicholl said, "and her brother James... and her sister Pippa." "While you certainly don't see them photographed together very often, they are very much there in the background," she added. "They are absolutely fundamental." According to Nicholl, the Princess of Wales, 42, "comes from a really solid, grounded family." "Everything her parents did as she was growing up was about raising that family, keeping them anchored, showing them love," Nicholl said, "and that's why Kate is the person that she is, and she's always so close." Video As Nicholl explained, when Kate married
Prince William and joined the
Royal Family, one thing she made him promise was that she wouldn't have to give up time with her own family because of it. Since she and William tied the knot in 2011, the Prince of Wales has actually become very close with his in-laws and been welcomed into Kate's family as well. As for how her parents are handling the news of their daughter's medical condition, Nicholl said, "I think they're going to feel very relieved that this was found in its early stages, and reassured by the fact that the chemotherapy is preventative chemotherapy. "Catherine is going to have the very best doctors in the world looking after her, so she's in safe hands," Nicholl added. "Carol and Michael, they've always been an incredibly strong couple and also very down to earth... what they'll be doing right now is they'll be coming together and supporting her -- and not just William and Kate, [but] their grandchildren, too." As ET previously reported, a month after the palace announced that King Charles III had been diagnosed with cancer , Kate revealed her cancer diagnosis in a video statement shared by Buckingham Palace . Although the mother of three did not share what kind of cancer she's battling, she explained that she's currently undergoing "preventative chemotherapy" and is "now in the early stages of that treatment." Kate said the news of the cancer diagnosis came as a "huge shock" to the royal family. She explained that she and William endeavored to manage the situation privately for the sake of their young children -- Prince George, 10, Princess Charlotte, 8, and Prince Louis, 5. "They have three weeks of Easter holidays with the children and I think the plans are... to lay low, to hunker down, to enjoy this time as a family," Nicholl shared. "They won't be photographed, they won't be seen, and they know that where they are, they're very well protected by the locals, and they can really enjoy a proper family holiday." Video ET learned that Kate and William , 41, were seen departing Adelaide Cottage in Windsor by helicopter on Saturday with their children to head toward Anmer Hall, located on the Sandringham Estate. The family will be spending the kids' Easter school break at their country home, which also gives them an opportunity to see the monarch. The Prince and Princess of Wales will not be attending Easter services with the rest of the family. This year's festivities will be a major departure from the family's typical lineup of events, which includes Easter service at St. George's Chapel in Windsor. A source added that it's possible the group could attend church in Sandringham together to mark the holiday. After Kate's diagnosis was revealed, a Buckingham Palace spokesperson shared that Charles is "so proud of Catherine for her courage in speaking as she did." Following their time in the hospital together, Charles has "remained in the closest contact with his beloved daughter-in-law throughout the past weeks, and both royals "will continue to offer their love and support to the whole family through this difficult time." Video