Prince William and Prince Harry's rift was detailed in the Duke of Sussex's memoir Spare which was released earlier this year.
In the tell-all book - and subsequent interviews - Harry alleged his 41-year-old physically attacked him and referred to William as his 'arch nemesis'.
While the Prince of Wales has declined to comment on the allegations publicly, Kate is reportedly using the fallout as motivation to ensure that their three young children, Prince George, Princess Charlotte and Prince Louis, avoid family rifts in the future.
Royal expert Kinsey Schofield told The Daily Star: "William and Catherine are determined to break the heir and the spare cycle.
"I don't believe the word 'spare' has ever been uttered inside their home to describe one or more of their babies. It is just not on their radar. They wanted to have a large loving family."
Prince George is the second in line to throne after his father, but William and Kate do not want the status to change him, or his bond with his siblings.
Harry's memoir was a nod to a term he claimed royal relatives used to refer to him.
The 38-year-old wrote that after he was born, King Charles III joked: "Now you've given me an heir and a spare - my work is done."
He went on to add: "They would say it without a spirit of judgement, but straight out. I was the shadow, the supporting actor, the plan B. I was brought into this world in case something happened to Willy."
However, Kinsey Schofield believes that Kate is educating her little ones on royal responsibilities and how to behave early on, which they are picking up swiftly.
She continued: "William and Catherine are teaching their children about royal responsibilities through doing them. You will notice how poised and prepared the children seem to be during large royal engagements.
"You can tell that Princess Charlotte takes great pride in her family and responsibilities. [It reminds] me of the Princess Royal."
