Rather than have them run riot inside the royal residence, Diana organised games for her children around the 900-acre garden.
He added: “Diana was very much a hands-on mother and would organize the Easter egg hunt, but she’d get all the staff involved hiding them.
“They had some chickens there and I remember someone suggesting hiding some of the eggs in the coop.”
Speaking to OK! magazine, Mr Wharfe added the royal children loved the Easter games Diana set up.
He told the outlet: “They’d be running around with no inhibitions trying to be the first to find them, badgering the staff to tell them where they were hidden.”
Mr Wharfe also shared Diana taught William and Harry to address royal employees by their first names.
He added: “There was no barrier between us staff and the princes – they were encouraged to use our first names.”
In 1994, Diana took her two children skiing in Lech, Austria over the midterm.
Mr Wharfe said the pair ”picked up skiing incredibly quickly” and “were fearless”, but added Diana “was incredibly good at it”.
The then-10-year-old Harry was eager to ski, with the former officer sharing: “I could see Harry was getting frustrated with having to follow the ski instructor.
“He just wanted to go fast, so he skied solo down a mountain and ended up in some mud and flowers.
“We had to go and dig him out! After that, we reminded him to stay with the group.”
After interviewing the Princess in 1991, Mr Morton released a biography about Diana which detailed how she raised Harry and William.
He shared in his books Diana often planned trips and holidays for her children, including the ski trip and days out to Thorpe Park.
Mr Morton claimed Diana rarely deferred to Charles or the family in decisions about her children.
In 2017, William recalled how Diana made sure he and Harry had fun as children.
In ITV’s documentary, Diana, Our Mother: Her Life and Legacy, which marked the 20th anniversary of Diana’s death, the Duke of Cambridge said his mother was “very informal and really enjoyed the laughter and the fun”.
He added: “She understood that there was a real life outside of palace walls.”
Harry also shared in the documentary: “Happy memories, big, smiley faces.
“She smothered us with love, that’s for sure.”