One of Princess Catherine (aka Kate Middleton) and Prince William‘s friends is speaking out amid her cancer battle.

The 42-year-old Princess of Wales announced over a month ago that she had been diagnosed with cancer and would be undergoing chemotherapy.

In a new interview, one of Kate‘s go-to designers expressed her concerns for the Princess amid her cancer treatment.

Keep reading to find out more… “I’m heartbroken at the moment. I think they are going through hell,” Amaia Arrieta shared with The Telegraph.

“I hope they will be back,” Amaia added. “It’s really personal.”

Kate has dressed her three kids – Prince George, 10, Princess Charlotte, 9, and Prince Louis, 6 – in Amaia‘s designs for years ever since Prince George was a baby.

“The first time I realized Prince George was wearing my designs, I was in Waitrose and saw the picture of him on the cover of Hello! magazine,” Amaia recalled. “That was a huge moment because they had been coming to us, but you never know if they’ll actually wear it.”

Amaia has continued to work closely with the children’s nanny Maria Teresa Turrion Borrallo design outfits for them for momentous occasions, including Princess Eugenie‘s 2018 wedding and the Royal Family’s annual church outing on Christmas Day.

“It’s often a very tight deadline. We would do anything for them – the children always look amazing in the end,” Amaia shared. “Dressing the royals gives me so much pride, I really do care about how they look.”

Prince William, 41, also recently provided an update on how Kate is doing.