Sources close to the couple say they are “closer than ever” after the 77-year-old Duke, who is the Queen’s first cousin, suffered a stroke in March.
The 80-year-old Duchess has not used her Royal Highness title since 2002, having largely withdrawn from royal duties.
She had been living apart from her husband but it seems she has moved back into their London home, Wren House at Kensington Palace.
A royal insider said: “The Duchess had been living at the couple’s Oxford home while her husband remained in London but it seems she has now moved back into Kensington Palace on a more permanent basis. They are closer than ever.”
The Duchess, who styles herself Katharine Kent, converted to Roman Catholicism in 1994 and soon afterwards began teaching music at Wansbeck Primary School in Longhill, Hull. After 10 years working secretly on its staff, she left in 2004 to launch her charity Future Talent, which helps talented young musicians.
She largely withdrew from public life, having been diagnosed with coeliac disease and Epstein-Barr virus, whose symptoms resemble those of ME or chronic fatigue syndrome .
Before that, she had presented the trophies to the winners at Wimbledon, a role now taken by the Duke, president of the All England Lawn Tennis and Croquet Club.