Kate Middleton’s monikers include the Princess of Wales and the Duchess of Cambridge.

However, according to Omid Scobie’s newest book “Endgame: Inside the Royal Family and the Monarchy’s Fight for Survival,” the 41-year-old royal has another “secret” nickname.

The expert has labeled Middleton — who tied the knot with Prince William in 2011 — as “cold” and as a “Stepford-like royal wife” who is “too scared” to undertake a heftier workload.

The biography has also claimed that her lighter amount of engagements make her “technically a part-time working royal.”

Middleton apparently “does not plan to increase her workload for 10-15 years,” until her children, Prince George, 10, Princess Charlotte, 8, and Prince Louis, 5, have reached mature age.

Kate Middleton
Omid Scobie’s newest book “Endgame” claimed that Middleton has a vicious nickname.AP
According to the book, the mother of three was also nicknamed “Katie Keen” because the royal family’s press office once claimed that she is “keen to learn” in an effort to draw attention away from her low amount of work events.

“Where other senior royals are out and about several times a week, meeting people across the length and breadth of the country, Kate has long maintained a smaller work schedule that helped her check off the required royal boxes while saving time for her roles as a mother and a wife,” Scobie wrote.

Prince Harry
Middleton apparently “does not plan to increase her workload for 10-15 years.”REUTERS
He added that the late Queen Elizabeth — who died in September 2022 — took a strong liking to the duchess because she was “coachable,” and could be molded into the perfect royal.

“The late queen, too, would take off blocks of time throughout the year to recharge, but she was also known to carry out at least three hundred engagements annually,” he said.

Scobie continued: “Sources said Kate remains ‘laser focused’ on her duty to the family first, and then the Crown.”

Queen Elizabeth
The late queen liked Middleton because she was “coachable.”Getty Images
The novel also alleged that Middleton and estranged sister-in-law Meghan Markle were encouraged to dress like the late Princess Diana.

The “Suits” star, 42 — who is married to Prince Harry — and Middleton “regularly replicated” Diana’s “iconic looks,” even wearing some of the People’s Princess’s old accessories.

“But while finding a trend untouched by Diana’s iconic style is almost impossible, the huge amount of effort that goes into channeling her exact look sometimes goes beyond the pale,” Scobie scribed.

“During the past thirteen years, Diana cosplay has become a royal staple,” he said.