Catherine, Princess of Wales, is set to attend her father-in-law King Charles III's birthday celebrations in June, the army said on Tuesday, her first official duty to be announced since undergoing surgery.
Royal officials have not formally confirmed her attendance but the British Army said Catherine, who is married to heir to the throne Prince William, will review soldiers on June 8 as part of the annual Trooping the Colour.
The king, who is currently being treated for cancer, is also scheduled to review troops at the Trooping the Colour main event on June 15, according to the army website.
Charles, 75, on Tuesday held an in-person audience with finance minister Jeremy Hunt ahead of the government's official budget announcement on Wednesday.
The British head of state, dressed in a blue suit and a light tie, was photographed shaking hands with Hunt as he welcomed him at Buckingham Palace in central London.
Charles, who became king in September 2022 following the death of his mother Elizabeth II after her 70-year reign, was diagnosed with an unspecified cancer last month.
Kate was on Monday spotted in public for the first time since she underwent abdominal surgery in mid-January, according to photos published by US outlet TMZ.
The 42-year-old princess has been recovering mainly at the home she shares with William and their three young children in Windsor, west of London, since leaving hospital on January 29.
The photos published by TMZ showed Kate wearing sunglasses while being driven by her mother in a car, with the celebrity news site saying they were taken Monday near Windsor Castle.
The sighting comes as social media has been alight with conspiracy theories over the princess's prolonged absence from the spotlight.
The illnesses of Charles and Catherine have given rise to a sense of uncertainty around the royal family, with William himself missing events to look after his family.
He also pulled out of a recent memorial service for his late godfather King Constantine II of Greece over an unspecified "personal matter".
Charles's wife Queen Camilla, 76, has been the most visible senior royal, stepping in to cover many of her husband's public duties as he undergoes treatment.
But she has now taken a break until March 11, when she is expected to join other senior royals at the annual Commonwealth Day service at Westminster Abbey.
She is reported to be on holiday this week, effectively meaning all four of the most senior royals are out of action.
William, 41, was last seen in public on Thursday during a visit to a London synagogue, where he condemned the rise of anti-Semitism in the UK.
He also attended last month's BAFTA film awards ceremony in London.
Kate's last public appearance was on December 25 when the royals attended a Christmas Day church service -- around three weeks before she was admitted to hospital for abdominal surgery.
Royal officials refused to say what she was being treated for but confirmed the condition was non-cancerous.
She spent almost two weeks in hospital, with Kensington Palace saying that she was unlikely to return to public duties until after Easter on March 31.
The princess, widely known as Kate, is one of the most popular -- and photographed -- members of the royal family.
Charles's younger son, Prince Harry, has quit royal duties for a new life in California while the king's brother Andrew stepped down from the public eye in 2019 after a disastrous television interview in which he defended his friendship with the late US sex offender Jeffrey Epstein.
The Daily Mail's veteran royal commentator Richard Kay said recent events made it was "impossible to escape the conclusion that it has suddenly become a threadbare institution".
