Kate Middleton and Prince William are "going through hell" as the Princess of Wales continues her battle with cancer, according to their close confidante and children's clothing designer, Amaia Arrieta. In a rare and concerning update, Arrieta, who has worked as a stylist for the Prince and Princess of Wales' three children since Prince George was a baby, shared her heartbreak over the couple's current situation.

"I'm heartbroken at the moment, I think they are going through hell, I hope they will be back. It's really personal," Arrieta told the Telegraph. The designer's remarks could indicate the seriousness of Middleton's condition, as she has refrained from revealing any personal information about the Waleses until now.

Arrieta, who owns her eponymous label Amaia, has been a go-to designer for the royal children's looks through the years. She expressed her pride in dressing the young royals, saying, "Dressing the royals gives me so much pride, I really do care about how they look."

The designer revealed that she works closely with the children's current nanny, Maria Borrallo, to ensure Prince George, Princess Charlotte, and Prince Louis always look their best, even under tight deadlines. "It's often a very tight deadline. We would do anything for them ... the children always look amazing in the end," Arrieta added.

Middleton, 42, is currently undergoing chemotherapy following her cancer diagnosis in March. The news came as a shock to the royal family and the public, with the Princess herself describing it as a "huge shock" in a self-written speech on March 22. In the video, Middleton revealed that post-operative tests from her "planned abdominal surgery" in January had shown the presence of cancer, leading to the start of her treatment.

The Princess of Wales emphasized the emotional toll the diagnosis has taken on her family, saying, "William and I have been doing everything we can to process and manage this privately for the sake of our young family. As you can imagine, this has taken time. It has taken me time to recover from major surgery in order to start my treatment. But, most importantly, it has taken us time to explain everything to George, Charlotte and Louis in a way that is appropriate for them, and to reassure them that I am going to be okay."

Prince William, 41, has recently resumed his royal duties and spoke briefly about his wife and children for the first time since Middleton shared her health update. When asked by a well-wisher about his family's well-being during a visit to the charity James' Place Newcastle on April 30, the Prince of Wales replied, "We're all doing well, thank you."

Middleton's cancer battle comes amid other health concerns within the royal family. King Charles, 75, announced his own cancer diagnosis in February, with the palace stating that he had "commenced a schedule of regular treatments" and would continue to carry out his duties as much as possible. Additionally, Sarah Ferguson, the Duchess of York, is currently battling an aggressive form of skin cancer.

As the Princess of Wales continues her treatment, her parents, Michael, 74, and Carole Middleton, 69, have stepped in to support their grandchildren during this difficult time. The Post revealed that the Waleses "sugarcoated" the news when breaking it to their youngest child, Prince Louis, but had a more "difficult" conversation with Prince George and Princess Charlotte.