According to royal rules, there are four family members who are "Counsellors of State," meaning they would take over for the Queen if she was unable to perform her duties.
Prince Charles, Prince William, Prince Andrew and Prince Harry are the four counsellors, however, Prince Andrew stepped down from his royal duties in 2019 after his relationship with late pedophile Jeffrey Epstein was exposed. Meanwhile, Harry, 37, moved to California last year with his wife, Meghan Markle.
"A Counsellor not domiciled in the U.K. cannot act, so that excludes Harry. The next in line and over the required age of 21 would be Princess Beatrice. However, most of the functions of the Head of State can be devolved. It is not, for example, constitutionally necessary for the Queen to attend the State Opening of Parliament," author Vernon Bogdanor noted.
The Queen was supposed to visit Northern Ireland at the end of October, but her visit was canceled after doctors told her to rest. After being hospitalized for one night, she was advised to lay low for the next few weeks.
"Following on from their recent advice that The Queen should rest for a few days, Her Majesty's doctors have advised that she should continue to rest for at least the next two weeks," the palace in a statement. "The doctors have advised that Her Majesty can continue to undertake light, desk-based duties during this time, including some virtual Audiences, but not to undertake any official visits. Her Majesty regrets that this means she will be unable to attend the Festival of Remembrance on Saturday, 13th November."
The statement concluded, "However, it remains The Queen's firm intention to be present for the National Service of Remembrance on Remembrance Sunday, on 14th November."
In the meantime, it seems like the Queen is trying to teach some of her family members certain things.
“She’s not a quitter and will continue working but is handing over some of her duties to Prince Charles and Prince William,” another source said. “[She] is preparing them to take over.”