Duchess Catherine has reportedly been dubbed "Duchess of Do-Little" by Britain's Queen Elizabeth.
The mother-of-two is believed to be facing mounting pressure from her royal relatives to make more of an effort with her official engagements after missing a planned lunch on July 10 in hour of World War II pilots, which has apparently angered her husband Prince William's grandmother.
An insider told Life & Style magazine: "She would never say this in public, but even Her Majesty described Kate as 'Duchess Do-Little' when she was very tired one day.
"She comes from a different generation and has a sense of duty above all else.
"Kate is getting a bit of a reputation for ducking out of royal duties. That's where her nicknames, 'Duchess of Do-Little' and 'Lazy Katie,' come from. If you can't find time to pay tribute to some old men who saved your country, what message does that convey?"
The 33-year-old royal's decision to miss the lunch came just two days after she attended the Wimbledon tennis championships and a fortnight after she hosted Brad Pitt and Angelina Jolie at Kensington Palace, much to the annoyance of other members of the royal family.
Princess Diana's former butler Paul Burrell explained the relationship between "royals and nonroyals" is usually difficult because of the pressures associated with being in the iconic family.
He said: "Relations between royals and nonroyals have always been awkward and tense.
"Marrying into the family firm is not easy."
However, the duchess is said to have had enough of the criticism and is refusing to be ordered around.
A source added: "Kate is fed up with sniping from the queen as well as from others in the family, and she has told William so. She is not going to be told which jobs she should and shouldn't do."