The 99-year-old left King Edward VII hospital in London following treatment for an infection and a heart condition.
The revelations come just days before a tell-all interview between Oprah Winfrey and The Duchess and her husband, Prince Harry.
The 99-year-old is being moved in order to continue treatment for an infection, “as well as undertake testing and observation for a pre-existing heart condition”.
The first episode is set to be a holiday special with stories of "hope and compassion" from special guests.
Japanese Emperor Naruhito's younger brother, Crown Prince Fumihito, was formally sworn in on Sunday as first in line to the Chrysanthemum Throne.
The former monarch officially recognised Delphine Boël as his daughter in January 2020 after DNA tests proved he was her father.
Beatrice, Queen Elizabeth's granddaughter, married her property tycoon beau in a private ceremony on Friday. The couple were initially scheduled to tie the knot on May 29 but the event was postponed due to the COVID-19 pandemic.
The British royals are both keen advocates of ethical fashion, but which are the labels they wear most?