Katie, who is the author of William and Harry: Behind the Palace Wall, claims Prince George is often “chosen” to spend more time with the Queen.
Talk to OK! she said her future as king “is being presented to her gradually” by William and Kate.
She said: “George is an absolute pleasure to be there and it’s up to his parents.
“They want to protect him from that point on, so it’s an idea that is being presented to him gradually. The real enormity of what his life will be like someday is not something he is yet fully aware of.
George is taken by his sister Princess Charlotte, five, and his brother Prince Louis, two, for photoshoots with his father, grandfather and great-great-grandfather whom Katie said she noticed.
Footage has been filmed of George learning to make Christmas puddings alongside his father, grandfather Charles and the monarch for the Queen’s Christmas Day message in 2019.
In January, a photo of George with the Queen and her son and grandson was released.
“I think George understands, as William did from a young age, that he is different from his younger brother and younger sister and that he will have a different future,” Katie said.
“After all, he’s being taken to do photoshoots with Her Majesty The Queen, so he must notice that he was chosen.
“But I don’t think William and Kate did much when they told George, ‘Someday you’ll be king.
“They don’t bring her up to be spoiled or to have an exaggerated sense of her own importance. He does not receive special treatment just because he is the future heir. ”
She said that William and Kate are believed to have chosen Thomas’ Battersea for Prince George’s early years of schooling because of its stimulating environment and emphasis on ‘kindness’.
“George’s arrival at school caused a lot of noise. Bulletproof glass was installed and the presence of protection officers sets it apart from its peers, she said.
“His classmates were clearly very aware that there was something different about him from the start. They know he’s a prince and they call him ‘PG’ which is short for Prince George.
Katie said the relaxed approach to preparing Prince George for his future could be due to what William felt as a teenager when he was troubled by the sense of duty that lay ahead.
She said: “As a young man, William really struggled with this notion of royalty. The realization that he had no choice but to what path his life would take, that he couldn’t become a doctor or a vet if he wanted to, weighed heavily on him.
“He was treated differently from his younger brother. When the boys went to tea with the Queen Mother, William had the first choice of sandwiches or cakes.
“It was all about William. I think that’s why Diana overcompensated in terms of affection for Harry because she was very aware that he didn’t have the same attention as William.
Katie said William and Kate, 38, who have stayed at their Norfolk Anmer Hall residence throughout confinement with their children, aim to make all young people feel equal.
She said: “They make it a point of honor that their three children feel equal and that they are all treated the same.”