Kate Middleton has reportedly earned the approval of Queen Elizabeth II. As a matter of fact, the 34-year-old Duchess of Cambridge is preparing to take part in the upcoming special tribute to honor the Queen's 90th birthday.

As part of a two-hour TV documentary celebrating the British matriarch's birthday, Duchess Kate is set for her first official TV interview since her engagement to Prince William in 2010. According to Closer Weekly, the royal mom-of-two has won the Queen's regard by "balancing" her royal responsibilities and motherhood with finesse.

"The queen thinks Kate is doing a great job as a young mum and is a wonderful wife to William," a royal insider told the publication.

The Queen also reportedly aims that bringing Duchess Kate into the fold will help her reach across the generation gap since her granddaughter-in-law is popular among younger Britons.

"She wants younger viewers in particular to learn more about her work over the best part of 70 years," the source added. "When Kate speaks, people listen. The queen knows that she will boost ratings. To be blunt, the queen wants some of Kate's stardust to rub off on her!"

As Queen Elizabeth II's 90th birthday looms, the Britain's longest-reigning monarch seems ready to slow down in juggling her royal public duties. In fact, People magazine cited some signs hinting the Queen is cutting down her royal engagements.

As per the publication, the Queen has been regularly appointing son Prince Charles and grandson Prince William to lead the investiture ceremonies, which the Queen usually does, at Buckingham Palace. The 89-year-old royal has also reportedly halted all "long-haul" travel.

In fact, palace officials said the Queen won't be traveling overseas at all on official business before the summer. In addition, Queen Elizabeth II and 94-year-old husband Prince Philip have also been gradually entrusting some of their 1,300 patronages and good cause to the younger members of the Royal Family.

The Duke of Edinburgh has also passed the role of patron of the Air Cadet Force to Kate Middleton in December. Rumors also have it that the Duchess will be taking over the patronage of the All England Tennis Club from the Queen while Prince Harry will get the Queen's England rugby patronage.

One major sign, however, indicated that the Queen appeared to be unready in taking a break from her royal duties. In fact, she's still doing more than 330 royal engagements annually, which is way more than the Duke and Duchess of Cambridge and Prince Harry's combined engagements they carried out last year.

Meanwhile, the Church of England has recently unveiled the logo that will be use during Queen Elizabeth II's 90th birthday celebrations.

The logo was drawn by 10-year-old Lucas Salinger from Potten End C of E Primary School in Hertfordshire, part of the Diocese of St. Albans. His design was selected from more than 1,000 entries from church schools that joined the design contest, Episcopal News Service reported.