The late royal's former private secretary Patrick Jephson tells PEOPLE she still inspires her sons "along the difficult path they were born to follow"

“We all remember the days when Harry and William were joshing with one another, and it all seemed set for their relationship and the future—that Harry, as Diana always used to say, would be William’s wingman,” Diana’s biographer Andrew Morton told People. “It’s a great loss for the monarchy.”

Princess Diana always had one wish for her sons Prince William and Prince Harry, but it has fallen apart after their ongoing rift left her hopes in tatters