The Duchess of Cambridge married the second heir to the throne Prince William in April of 2011. Last month, the couple celebrated their tenth wedding anniversary.
Royal author Ingrid Seward explained that the Queen and Prince Philip approved of Kate as a future Queen consort.
Speaking to Fox News in November, Ms Seward Queen Elizabeth II probably prays to God “Thank you for sending us Catherine Middleton”.
Ms Seward added: “She is a gem.”
The royal expert added how the Duchess has been accepted by the Firm and has developed a close bond with the Queen.
READ MORE: ‘Friendly’ Kate Middleton’s gift to young girl with adorable message
“I think when the time comes, Kate will use that title and so comparisons are automatically going to be made with Princess Diana.
“And of course they’re very big shoes to fill and I think that’s why Kate if you like has tried to beef up over recent years her own individual commitment to the crown.
“That means not being in her husband’s shadow but doing her own thing.
“The closet comparison might be a sort of first lady to presidential role in that Kate wants her own office, her own advisers and her own pathway to follow in addition to that of being in union with Prince William.”
The Duke and Duchess of Cambridge have three children together – Prince George, seven, Princess Charlotte, six, and Prince Louis, three.