Prince and Princess of Wales have joined the rest of the royals, without the Duke and Duchess of Sussex, at Scotland’s Balmoral Castle.

Kate Middleton is prioritizing her health as the rift between Prince William and Prince Harry continues to deepen.

The Princess of Wales, who is battling an undisclosed form of cancer, was seen arriving at Crathie Church on the Balmoral Estate on Sunday. The 42-year-old was being driven by her husband.

The royal family traditionally spends the rest of the summer months together in private at Balmoral Castle. Queen Elizabeth II loved the sprawling, 50,000-acre estate, calling it her “paradise in the highlands,” according to Perthnow, an Australian website.

Kate Middleton was spotted in Scotland over the weekend alongside her husband Prince William. (Samir Hussein/Getty Images)

Sources previously told People magazine that Harry and his wife, Meghan Markle, were not invited to join the rest of the royals.

Christopher Andersen, author of “The King,” told Fox News Digital that while Kate and Harry were once close, she isn’t leading any peace talks between the battling brothers anytime soon.

Kate Middleton continues to prioritize her health as the rift between Prince William (right) and Prince Harry (left) deepens. (DOMINIC LIPINSKI/POOL/AFP via Getty Images)

“Kate was close to Harry, true,” Andersen explained. “They had a special bond. They shared the same goofy sense of humor and laughed at the same jokes. Harry often said Kate was the sister he never had. Of course, Kate would like nothing better than to have the brothers kiss and make up.  It would be one less cloud hanging over the royal family’s head.”

Prince Harry (right) was once close to his sister-in-law Kate Middleton (center). (Jeff Spicer/Getty Images)

“But above all else, Kate is loyal to her husband,” Andersen shared. “She understands completely why William is still fuming. Kate is not about to pressure William while he has so much on his plate, notably her cancer and the king’s cancer battle as well.”

“The last time Harry was at Balmoral Castle was in September 2022, when his grandmother, Queen Elizabeth, died there,” Andersen pointed out. “His absence from Balmoral this summer is just one more sign that the royal family – Kate included – prefer to have Harry out of sight and out of mind for the time being.”

Christopher Andersen, author of “The King,” told Fox News Digital that the last time the Duke and Duchess of Sussex were in Balmoral was in September 2022, when Queen Elizabeth II died. (Kirsty OConnor – WPA Pool/Getty Images)

Sources recently claimed to U.K.’s Closer magazine that the mother of three “has been shielded from the increasing drama with the Sussexes for quite a while now.” Still, the Princess of Wales remains “very concerned.”

Balmoral Castle is a well-known summer retreat for the British royal family. King Charles III is currently there hosting family members. (Tim Graham Photo Library via Getty Images)

“Kate looks at Harry, and she sees a very lost soul,” one source claimed to the outlet. “She’s still incredibly fond of him and so saddened that it’s come to this situation where he’s completely excommunicated himself from the whole family and there now seems to be this wall that can’t be broken down.”

Andersen agreed with the claims.

“But above all else, Kate is loyal to her husband. She understands completely why William is still fuming. Kate is not about to pressure William while he has so much on his plate, notably her cancer and the king’s cancer battle as well.”

— Christopher Andersen, author of “The King”

Prince William, who is heir to the British throne, is returning to royal duties in September. (Mikolaj Barbanell/SOPA Images/LightRocket via Getty Images)

“Kate made an effort to bring the brothers back together in the beginning,” Andersen claimed. “One of the most poignant scenes in this whole saga was during Prince Philip’s funeral in April 2021, when Kate was seen stepping aside so the brothers could be together as they left the funeral service and walked up the hill to Windsor Castle.”

According to reports, Prince William and Prince Harry aren’t on speaking terms. (Justin Setterfield/Getty Images)

“When that didn’t work, Kate continued to try and soften up her husband,” he said. “But Kate understandably threw up her hands when Harry trashed William and Charles in his memoir ‘Spare’ two years later.”

In March, Kate announced that she had been diagnosed with cancer and was undergoing chemotherapy. The announcement came after relentless speculation on social media ever since January when she was hospitalized for unspecified abdominal surgery.

At the time, the British royal requested “time, space and privacy while I complete my treatment.”

Kate Middleton announced to the world she had cancer in March 2024. (The Prince and Princess of Wales Twitter)

The princess later admitted in a personal letter that “there are good days and bad days.” She also expressed her desire to attend “a few public engagements over the summer, but equally knowing I am not out of the woods yet.”

Kate went on to attend Trooping the Colour in June and Wimbledon a month later. She skipped Garter Day, Royal Ascot and a Japan state visit to the U.K.

“Harry and Meghan are not on the Prince and Princess of Wales’ radar right now,” Kinsey Schofield, host of the To Di For Daily podcast, claimed to Fox News Digital. “Catherine is still receiving chemotherapy, is still exhausted, and is focused on her health and family.

From left: Prince George, Prince William, Prince Louis, Princess Charlotte and Catherine, Princess of Wales on the balcony of Buckingham Palace during Trooping the Colour on June 15, 2024, in London. (Karwai Tang/WireImage/Getty Images)

“The bigger picture no longer includes Harry,” Schofield claimed. “[The royals] are focused on Kate’s health, the future of their family, and the future of the crown.”

Harry has had a strained relationship with his family and has seen his father infrequently since he and his wife quit royal duties in 2020. At the time, the couple said the unbearable intrusions and racist attitudes of the British press were what had prompted them to step back as senior royals. The father of two has since detailed his rocky relationship with his family in TV interviews, a documentary and his memoir, “Spare.”

In “Spare,” Prince Harry detailed his sibling rivalry with Prince William. (Yui Mok – WPA Pool/Getty Images)

When Harry returned to London in May to mark the 10th anniversary of the Invictus Games, his spokesperson issued a statement, implying that his father, King Charles III, was too busy to meet with his son. According to reports, William and Harry aren’t on speaking terms.

In January 2023, Prince Harry sat down with “60 Minutes,” one of several televised interviews he gave, to promote his memoir, “Spare.” He recounted his childhood, the loss of his mother and his rift with the royal family. (CBS via Getty Images)

“Princess Catherine was raised in a happy family without either sibling rivalries or parental infighting,” royal expert Hilary Fordwich explained to Fox News Digital. “She values family stability and part of her calmness originates from that stable, sturdy family background. In contrast, Prince William was witness to bitter infighting between his parents, the late Princess Diana and the current king.”

“The recent betrayals by Prince Harry have cut William to the core,” Fordwich claimed. “He was devastated by the revelations in ‘Spare.’ Now, of course, he cannot trust his brother, once closest to him.”

“Those closest to the Princess of Wales have been protecting her from this current rift, but it is disquieting to her,” Fordwich added.

Kate Middleton returned to her beloved Wimbledon in July. (Getty Images)

Royal expert Ian Pelham Turner claimed to Fox News Digital that royal watchers may see the Sussexes in the U.K. soon – but for a different reason.

“I have received information from a source close to William that Meghan will be working extensively across Britain with her husband on what appears to be a major PR campaign,” Pelham Turner claimed. “They intend a massive return to public life, I am told, to bolster further their presence. [But] I think it will leave little time for reconciliations… more like an all-out war to obliterate the perceived opposition.”

Meghan Markle, an American actress from California, became the Duchess of Sussex when she married Britain’s Prince Harry in 2018. (Juancho Torres/Anadolu via Getty Images)

“As much as I wish them to succeed and King Charles and Camilla to enjoy their round of global events, they are not a united royal family,” Pelham Turner claimed. “[They’re] a family in total disarray… [But] I live in eternal hope as an eternal optimist.”

The Duke and Duchess of Sussex (left) stepped back as senior royals in 2020. They reside in the wealthy, coastal city of Montecito in California. (Max Mumby/Indigo/Getty Images)

It’s unclear when Kate will officially return to public duties. The Duke and Duchess of Sussex continue to carve out roles for themselves in California, where they reside with their two young children.