Although they are separated in age by 56 years — the Queen and Kate share key qualifications for their royal roles: quiet stoicism, unerring discretion and firm loyalty.
However, the two women diverge in their approach to family life — likely a reflection of their generational differences and backgrounds.
Kate — who is mom to Prince George, 9, Princess Charlotte, 7, and Prince Louis, 4 — "is not royal by birth, so she has that belief that she should spend time with her children," an insider tells PEOPLE in this week's cover story.
In contrast, the Queen was born into royalty and acceded to the throne at age 25 following the sudden death of her father, George VI, in 1952. At the time, she was already a mother of two.
Anwar Hussein/WireImage Kate Middleton and Queen Elizabeth
It "was very difficult for her to blend that role of wife and mother and head of state. She didn't have any role models," the Queen's biographer Sally Bedell Smith tells PEOPLE.
"Her mother [Elizabeth] had been a very good Queen Consort"—the same title, as wife of the monarch, that both Kate and Camilla, Duchess of Cornwall will one day acquire—"and Elizabeth had learned some from her father. But in a way, she had to develop her own approach to being Queen," Bedell Smith adds.
Samir Hussein/WireImage Prince William, Kate Middleton, Prince George, Princess Charlotte and Prince Louis joined Queen Elizabeth and Prince Charles on the Buckingham Palace balcony on June 5.
The Queen relied on nannies and staff to care for her young children, and she and her husband Prince Philip were often gone for long periods of time on tours and official duty. Much has changed when it comes to parenthood in the monarchy. As new parents, William and Kate brought Prince George with them on their tour of Australia when he was just a year old.
Kate's hands-on approach to parenting isn't the only way she's put a modern spin on her role within the royal family. Kate's campaigning on social issues like early childhood development sets her apart from her mentor; she sees that work as a defining mission for decades to come.
Because of her role as head of state, the Queen has not been in the same position to single out particular issues to champion.
However, they both share a natural affinity for connecting with the public. Kate, like the Queen, is "able to make each person feel that they are being seen for the three seconds she talks to them," says author and historian Amanda Foreman, author of Queen Victoria's Buckingham Palace.
GEOFF PUGH/POOL/AFP via Getty Queen Elizabeth, Prince William and Kate Middleton
For more on how Kate Middleton has the perfect role model in the Queen, pick up a copy of the latest issue of PEOPLE on newsstands on Friday.
This quality, adds Foreman, "projects immediacy and makes it feel intimate, which is amazing—there are people who simply can't do that. It is training plus innate talent."
Joe Giddens/PA Images via Getty Kate Middleton, Princess Charlotte and Prince William
This week, family and duty merged for Kate and Prince William when they attended the Commonwealth Games — and brought daughter Charlotte along for her first solo outing alongside her parents.
They "are representing the Queen impeccably," says author Sally Bedell Smith adds of William and Kate. "They're showing a kind of dedication she would be proud of. And that probably gives her hope."