She added: "Maybe now, through her grandchildren, she can see how to stay on top of that wave."
Bullen said he believes Prince Charles is more than ready to become King, but said he doubts it will happen before he turns 80.
He also suggested that many of the royals believe that he was becoming a King that eventually killed the Queen's father, King George.
He died of lung cancer at age 56, but there were many reports that he smoked excessively due to stress and anxiety.
Mr. Bullen said: "His mother lived to be 101. The Queen is there long term, she could live at least another 10 years."
"She has seen everything, she has done everything, she is the best working and working mother, and I do not think she will go anywhere, in the short term."
In 1936, Edward VIII ascended the throne after the death of his father George V.
He proposed to Wallis Simpson, his American lover, to cause a national scandal since she had already divorced twice.
The Church of England refused to marry them on that basis, and Mrs. Wallis went to live in exile in France.
In December 1936, Edward abdicated to marry her, forcing his brother George VI, the Queen's father, to claim the throne.
In 2017, Charles was named successor to the queen as head of the Commonwealth.
She has been giving him royal duties, and younger members of the royal family such as Meghan Markle and Prince Harry, ever since.