From dancing like an elephant to counting down the days to her wedding, they offer a rare insight into the life of one of the 20th century's most photographed and best-loved women: Diana, Princess of Wales.

From dancing like an elephant to counting down the days to her wedding, they offer a rare insight into the life of one of the 20th century's most photographed and best-loved women: Diana, Princess of Wales.

And yesterday, four letters from Diana to her ex-nanny raised £21,100 at auction, well over the asking price.

The previously unseen letters were sent to Mary Clarke, 58, who now lives at Fleggburgh, near Yarmouth, and show that their bond remained close long after they went their separate ways.

She wanted to auction the letters to give the public a charming glimpse into the rapid change of Diana from girl-about-town to princess. Ms Clarke was 21 when she applied to be nanny to Diana and her brother Charles, a post she held for two years.

The letters also show Diana's fun side, with her likening her dancing to that of an elephant, owning up to breaking furniture and being impatient to marry Prince Charles.

It had been estimated that the letters would raise about £7,300 at yesterday's sale of 75 royal lots at Colchester-based Reeman Dansie.

Later, Ms Clarke said: “Although the letters have gone from my possession, the very fond memories of my precious time with Diana will continue to live on. I am just pleased that people have been able to gain an insight into her life, from being a girl around town to a princess.”

The highest bid of £9,200 was for a letter in which Diana, then 17, wrote: “My love of my life is dancing, things like tap, modern, ballet and jazz. Also I love singing, even though my voice sounds awful, and watching me dance is like watching an elephant.”

Another, written four weeks before her wedding at St Paul's Cathedral in 1981, went for £2,200 and shows that Diana was getting bored with waiting to go down the aisle. It reads: “Not to long to go now and about time too!

“Six months of being engaged is quite something and definitely to be avoided. All the family are in complete overdrive!!”

A letter thanking Ms Clarke for sending Diana and her fiancé an engagement card fetched £1,700. The last lot, featuring a letter from Janu-ary 1982 in which Diana mentioned feeling ill when she was pregnant with Prince William, raised £8,000.

In the correspondence the princess also refers to a trip to her family home with her husband, saying: “I took him to Althorp for the weekend which was alright, except that in our short stay we managed to break two Stuart chairs and a glass window.”

Diana continued to write to Ms Clarke until five years before her death in Paris in 1997.

Ms Clarke has another six personal letters from Diana, and, despite being offered a blank cheque for them, she has said she will keep them locked up in a bank vault forever.