One of Kate Middleton and Prince William’s friend shared that the royal family’s difficulties have become “really personal” amid the Princess of Wales’ cancer battle.

Kate Middleton and Prince William are experiencing a difficult period.

As the Princess of Wales continues to battle cancer, one of the couple’s go-to designers Amaia Arrieta shared that she’s keeping the royal family in her thoughts.

“I’m heartbroken at the moment,” she told The Telegraph in an interview published May 2. “I think they are going through hell—I hope they will be back. It’s really personal.”

Amaia went on to explain how honored she feels to have helped dress the royals, ever since Prince George, 10, wore her brand’s Amaia corduroy shorts in a 2014 Christmas photo. More recently, Princess Charlotte was pictured in her label’s checked skirt in the Mother’s Day photo that sparked an editing controversy.

“Dressing the royals gives me so much pride, I really do care about how they look,” the designer told the outlet. “They have put the traditional and classic way of dressing children on the map.”

Kate and her kids George, Charlotte and Prince Louis, 6, have remained out of the public eye for the most part ever since she underwent abdominal surgery in January. In March, the 42-year-old explained in a video that further testing showed an unspecified type of cancer had been present.

“My medical team therefore advised that I should undergo a course of preventative chemotherapy and I am now in the early stages of that treatment,” she continued. “This of course came as a huge shock, and William and I have been doing everything we can to process and manage this privately for the sake of our young family.”

In the meantime, William has been making occasional public appearances, including at the grand opening of James Place Newcastle on April 30, where he told well-wishers that his wife and children were doing alright.

“All doing well, thank you,” William shared. “We’re all doing well.”