James, Pippa and Carole are set for pivotal behind-the-scenes roles as Princess Kate receives cancer treatment, a royal commentator exclusively told GB News.
The younger brother of the Princess of Wales was the first family member to publicly take to social media following Kate's emotional cancer announcement.
Kate, 42, recorded a video last month from Adelaide Cottage to announce she had begun a course of preventative chemotherapy.
The princess initially underwent abdominal surgery in January, which meant she had to spend 13 days inside The London Clinic.
Carole, Pippa and James Middleton will support the Princess of Wales
Getty
Following the operation, it became clear through tests that cancer had been present.
After Kate's video announcement, James, 36, took to Instagram with an old picture of himself and his sister from their childhood.
He captioned the post: "Over the years, we have climbed many mountains together. As a family, we will climb this one with you too."
Gareth Russell, a royal author and biographer of the late Queen Mother, spoke exclusively to GB News about the pivotal role James, Pippa and Carole will play during Kate's course of treatment.
James Middleton posted this childhood image of himself and Kate on InstagramInstagram / James MiddletonHe said: "James has an Instagram account and his tribute to his sister was heartfelt and beautiful.
"Especially after just that onslaught of speculative horror that surrounded the princess and in the weeks before, which I cannot imagine was easy for anyone who loved her and who knew what she was actually going through, that must have been immensely difficult."
Russell noted how the paparazzi have photographed members of the Middleton family.
He added: "We have seen Carole Middleton with the princess, one of those photographs captured by the paparazzi on the American website, TMZ."
Kate shared her cancer diagnosis with the world via videoPA LATEST ROYAL NEWS:
Pippa Middleton and Kate are two years apart in ageGettyKate's immediate family live in Berkshire and very rarely speak to the press, choosing to protect their privacy.
Russell stressed that James, Pippa and Carole would concentrate on taking care of Kate "behind the scenes".
He explained: "However, I think again, we won't see much of them.
"That is because the Middletons do very much prefer to keep things private."