Kate Middleton and Prince William were noticeably absent during the Middletons annual holiday in the Caribbean island of Mustique. The Duchess of Cambridge’s parents Carole and Michael Middleton arrived at the island retreat last week. The British royal couple accompany Kate’s parents every year during their traditional getaway and also usher in Carole’s birthday on Jan. 31.

However, this year Kate and William have been inconspicuous by their absence. It is possibly because little Prince George has started going to nursery school in January. The royal couple reportedly did not want to upset their son’s schedule at the Westacre Montessori School in East Walton.

It was reported on Monday that the tot has adapted himself well to his new school. Besides, Kate and William’s baby daughter, Princess Charlotte just turned nine months Tuesday. If the couple would have traveled to the Caribbean island they would have to take a long flight, which would have put Charlotte in problem.

However, it was anticipated by royal watchers that Kate and William would join the Middletons at Mustique and celebrate Carole’s 61st birthday. The couple regularly go on the outing to celebrate Kate’s mother’s birthday with her family. Carole and Michael were spotted at the Cotton House Hotel where they put up every year with their friends.

Meanwhile, this year is expected to be a busy year for the Duke and Duchess of Cambridge. Apart from tending to two small kids at their country home in Norfolk, the couple will go on their first overseas official tour of India and Bhutan in April. Both Kate and William are getting ready to celebrate the 90th birthday of Queen Elizabeth II in June.

Kate is continuing her solo engagements, of which her nearest is guest editing Huffington Post on Feb. 17. Besides, she has recorded her first official interview since her engagement to William. It will be aired as part of the documentary to mark the birthday of the queen.