Prince Harry will be in the UK next week for charity events, but it is not known if he would stay for the funeral, which is expected to be attended by many senior royals.
The Prince and Princess of Wales said she would be a “much missed member of the family” who had “worked tirelessly to help others and supported many causes, including through her love of music”.
Prime Minister Sir Keir Starmer said the Duchess of Kent brought “compassion, dignity and a human touch to everything she did”.
The duchess supported music charities and taught music at a Hull primary school, where pupils knew nothing of the royal background of “Mrs Kent”.
She will be remembered as a familiar figure at the Wimbledon tennis championships, where she handed over trophies – and consoled those who had lost, famously including a tearful Jana Novotna in 1993.
Tennis player Martina Navratilova posted a tribute with a picture of herself and the duchess at Wimbledon, saying it was “amazing how many millions of people around the globe she affected in a positive way”.
The duchess, who stepped back from her royal life in her later years, had supported charities including Childline and the Passage, which supports homeless people, based in Westminster not far from where her funeral will be held later this month.