Kate Middleton's one female royal relative who has been tower of strength in difficult year

has received support from her husband and family during her health struggles this year, but another female has also been a source of comfort.

Royal biographer Claudia Joseph revealed that has been a "tower of strength" for Kate.

Claudia told : "I'm sure that Sophie has been a tower of strength through Kate's cancer diagnosis and will be there for her at the end of the phone whenever she wants a chat."

The two women, who live just 11 miles apart, have developed a close bond, evident in their interactions at the Remembrance service in London, where Sophie was seen placing a supportive hand on Kate's back at the end of the service.. Claudia added: "They are incredibly close and live only 11 miles from each other – Kate in Adelaide Cottage in Windsor Home Park and Sophie at Bagshot Park.

"Interestingly, while Meghan rebuffed Sophie's offer to mentor her on life as a royal, Kate gracefully jumped at The Queen's suggestion – she saw her as a solid and trustworthy member of The Firm - and the women have become close as Kate adapts to her new role as .

"She has found that Sophie is a true confidante and sounding board and they have developed a mutual respect and an unbreakable bond."

READ MORE:

Kate and Sophie also shared a number of supportive glances at one another as they watched the proceedings from a balcony.

It has been reported that another member who has been a tower of strength for during the previous 11 months is none other than King Charles, reports .

He was diagnosed with cancer just as his daughter-in-law was, and their relationship appears to have grown stronger during this challenging time. The two underwent treatment at around the same period in January, where it's said they supported each other considerably.

A source familiar with King Charles shared with The Times: "The King has always had a close, warm and unique relationship with the princess. She has a great love and respect for him and his position. When they were in hospital together there was a lot of toddling down the corridor to spend time with her. He has been encouraging and supporting her throughout."