A third teaser for the tell-all interview was recently released, in which the Duchess of Sussex was seen referring to the royal family as 'The Firm.'
The 99-year-old was first admitted to King Edward VII's hospital in London on February 16.
Queen Elizabeth II and Prince Philip posed for a photo at the Balmoral Castle library to celebrate World Book Day.
Camilla is the second member of the royal family to publicly say that they are "keeping their fingers crossed" for the Duke.
Queen Elizabeth II's former press secretary Dickie Arbiter claimed the bedside visit was so Prince Philip can discuss succession with Prince Charles.
The producers of the interview are reportedly refusing to postpone airing despite Prince Philip's deteriorating health.
Doctors will continue to treat the Duke "for an infection, as well as undertake testing and observation for a pre-existing heart condition."
The Queen joked about the statue of herself presented to her by officials in South Australia during a video call.
The interview titled "Oprah With Meghan and Harry" will be aired on CBS Network on March 7.
Prince Charles, in particular, is making a real effort to step up for his mother amid his father's hospitalisation.
Meanwhile, Sophie Wessex recently began volunteering at St John Ambulance and the NHS at a vaccination centre in Greater London.
The interview was Charles and Diana's first as a couple, and also the biggest media story at the time.
The Duke of Edinburgh will have to extend his hospital stay although he is said to be responding well to treatments.
Prince Philip is doing fine and getting the help he needs as he remains in the hospital for nearly a week now.
The revelation comes after Westminster Abbey announced that it will not be hosting the annual Commonwealth Service on March 8.
The palace will reportedly have to make extra arrangements if the Duke and the Duchess of Sussex plan to attend the event.
The position could have gone to Prince William, but he won't be chosen for it to avoid it being seen as provocative.
The Duke of Edinburgh was taken to the King Edward VII Hospital in London's Marylebone on Thursday night.
Susannah Constantine was invited to a dinner party at Queen Elizabeth II's Windsor Castle in Norfolk several years ago.
Somerley Estate in Hampshire and Wilton House in Wiltshire feature in both the period dramas.
Prince Donatus of Hesse(Germany), a third cousin of the British monarch, has loaned his property in Hesse for the movie.
The film was eventually forgotten but gained renewed interest last year after an episode of season three of the hit Netflix series "The Crown" focused on it.