Queen Elizabeth II’s friends dare not ask her about her personal feelings because of the wall of privacy around her, according to a US journalist given access to the British monarch’s entourage for a new biography.

The most public and the most private person in the world

Elizabeth the Queen, by Sally Bedell Smith, is already a hit on both sides of the Atlantic as Britain starts commemorations for the monarch’s Diamond Jubilee.

Ms Bedell Smith, a writer for Vanity Fair, has produced biographies of Princess Diana, John and Jacqueline Kennedy, and Bill and Hillary Clinton.

She was given tacit approval by Buckingham Palace for her latest project and spoke to advisers, courtiers and relatives of the woman she calls “the most public and the most private person in the world”.

In the book, Ms Bedell Smith tells of the Queen’s fears over the divorce between her son Prince Charles and the late Princess Diana and many other dramas in her reign.

Speaking in New York, the American author and historian said that the Queen has devoted friends but, because she lives in her own little bubble and own little world, it is a different kind of friendship.

“She tries to be amusing and she gives them very good advice, although they are very careful about not being presumptuous and calling upon her for that,” Ms Bedell Smith said.

“She is very interested in their families and what is going on. But there is a kind of a scrim in front of her

“They dare not really ask her about her personal feelings and personal life. She keeps a lot of that to herself. One of her cousins told me that, when she gets frustrated – there is a weed in Scotland called the sticky willy – she goes out into the fields and pulls it up.”

Queen Elizabeth ascended to the British throne on February 6, 1952 after the death of her father King George VI.

Mass national commemorations of her reign are to be held from June 2-5.

The biography reveals the Queen’s fears after the 1996 divorce of Prince Charles and Princess Diana.

The former Archbishop of Canterbury, Lord Carey, says in the book that Queen Elizabeth was worried that her eldest son would give up his place in the line of succession for Camilla, just as King Edward VIII gave up the throne in 1936 to marry his mistress, Wallis ­Simpson.

The book says there were strains in the Queen’s own marriage to Prince Philip after she refused to take his family name, Mountbatten, following their 1947 wedding and Elizabeth’s accession to the throne. Her family and the government had insisted on keeping the Windsor name.

But Ms Bedell Smith writes that Prince Philip has been a devoted husband and disputes reports that he has had multiple affairs.

“What struck me was how much they are in synch,” she said at the reception.

The monarch, who has never given a media interview in her six decades on the throne, cannot express political views but is portrayed as a traditional conservative, unimpressed by the New Labour moderate socialist philosophy of Tony Blair when he was Prime Minister.

Queen Elizabeth’s softer side is shown in her attendance at the 80th birthday party of another former Prime Minister, Margaret Thatcher, who had been weakened by several strokes.

The biography reveals the queen’s fears after the 1996 divorce of Prince Charles and Princess Diana

Normally it is banned for people to touch the Queen. But as Lady Thatcher curtseyed, the monarch held Lady Thatcher’s hand to steady the ailing former political leader.

The Queen then guided Lady Thatcher through the crowds at the reception.

Ms Bedell Smith said that with most of her subjects she had found out details that had made her disillusioned with the characters involved.

But not with the Queen. “She has a natural modesty. She is so driven and yet so sensitive.”