
At one time, Princess Kate and Prince William appeared to be extremely close to Prince Harry. In fact, the trio would regularly conduct official royal engagements together, and Kate's rapport with her brother-in-law seemed clear. However, Harry and William's estrangement allegedly changed the Royal Family's dynamic, and according to one royal author, Princess Kate might have predicted the fallout.
In the new royal biography, William and Catherine: The Monarchy's New Era: The Inside Story, royal expert Russell Myers discusses Kate's involvement in Harry and William's sibling relationship. "The true disintegration of William and Harry's bond would not occur until many years later, but Catherine witnessed their competitive nature and often acted as a peacemaker," the author claimed.
According to Myers, Princess Kate's childhood as part of the Middleton family meant she always attempted to keep familial relationships cohesive. "Her upbringing in a close-knit, loving family environment, where supporting each other was almost an unofficial family motto, spurred her actions," Myers claimed.

Myers continued, "Whether counseling William or having a quiet word in Harry's ear, she saw it as her duty to keep the two brothers on the same team, as did their senior aides."
In an interview with Marie Claire's senior royal editor, Kristin Contino, author Myers revealed that Prince William actually questioned the way Prince Harry was treated as a child. "The issue of treating the 'heir and spare' as completely separate entities is something William has always wanted to change," Myers shared.

Myers continued, "It's not how he and Catherine have brought up their own children and William saw fundamental problems with the different treatment he was given as a child to his brother. In his view, it wasn't healthy.”
Perhaps, in the future, Prince William, Prince Harry, and Princess Kate will be able to repair their fractured relationship, after all.