SHE was once dubbed the Royal family’s “peacemaker” and was seen as instrumental in trying to help feuding brothers William and Harry heal their rift.

But Kate Middleton’s own relationship with her estranged brother-in-law is almost irreparable after he made “snide” remarks about her, a royal expert has claimed.

Royal expert Katie Nicholl claims there has been a ‘complete breakdown of the bond’ between Prince Harry and Kate MiddletonCredit: Getty

Kate and Harry used to be ‘very, very close’ before the Megxit falloutCredit: AFP

The royal expert said Harry ‘broke Kate’s trust’ with his ‘snide remarks’ in SpareCredit: Paul Edwards – The Sun

The Princess of Wales came under attack by Prince Harry in his autobiography, Spare, which was released earlier this year.

And while almost 10 months have passed since the book’s release, royal correspondent Katie Nicholl says Harry’s decision to publicly criticise his sister-in-law is still something that deeply upsets her.

Katie, author of The New Royals, told Fabulous: “When you think of the personal revelations, and I think you can call them snide remarks made about Kate in Spare, Harry broke the one rule and that is staying silent on family matters.

“While Kate and Harry used to be very, very close, there’s been a complete breakdown of that relationship.

“I don’t think Kate does angry. I think it is more a case of feeling very disappointed, very let down and feeling hurt knowing that she had no right of reply – and Harry knew full well she had no right of reply.”

Katie added: “I do know that William was very angry that Harry had drawn Kate into it when he felt Kate was blameless throughout. She acted very much as the peacekeeper, she tried to get the brothers back on an even keel and for Kate to be dragged into this mucky saga was upsetting for her and certainly did infuriate William.”

In his autobiography, Harry claimed Kate, 41, was “disgusted” when Meghan used her lip gloss, and he recounted another row where the Cambridges were “apparently upset that [the Sussexes] hadn’t given them Easter presents”.

The 39 year old prince also went into detail about the infamous row over Princess Charlotte’s bridesmaid dress when he married Meghan, 42, in 2018.

And in a further break in Kate’s trust, Harry revealed how a row between the two women broke out after Meghan suggested a then pregnant Kate had “baby brain.’

He claimed that Kate told Meghan, “You talked about my hormones! We are not close enough for you to talk about my hormones!”

He wrote that Kate gripped “her chair so tightly her fingers had turned white.”

And according to Katie, it isn’t just Kate’s relationship with Harry that is beyond repair, but Kate and Meghan’s too.

“I think it’s too far down the line for Kate and Meghan,” the royal expert said. “There were some deeply personal revelations about Kate in the book.

“Meghan clearly didn’t enjoy her time here and she’s obviously leading a much happier life in California.

“She is certainly in no hurry to come back to Britain [to reconcile], though she was certainly in a hurry to leave!”

Meanwhile, Katie says that Prince William’s relationship with his younger sibling is so “challenging” and “badly broken” that he also has no intention of making amends with Harry, despite them both being in America this week.

William, 41, is currently in New York for the Earthshot Prize Summit, while Harry and Meghan returned to California this week following their stint in Germany for the Invictus Games.

Katie said: “There have been many occasions where William and Harry could have they could have met and attempt to reconcile – there was obviously the King’s coronation, William’s trip to Boston, Harry has recently been in the UK – there are times when they have been in the same country and they have no plans to meet.

“I think that tells you everything you need to know about the state of their relationship.

“There has been a complete breakdown of trust. I think even if William did want to reconcile, the trust between him and his brother has been so badly broken down that I think it’s going to make any reconciliation very, very challenging.”

In his autobiography, Harry claimed Kate, 41, was ‘disgusted’ when Meghan used her lip glossCredit: Getty

The trio used to champion charitable causes togetherCredit: AP:Associated Press

Katie Nicholl said Harry ‘broke the one rule and that is staying silent on family matters’Credit: Getty

Prince Harry and Kate have often enjoyed joking together in the pastCredit: Paul Edwards – The Sun