The Queen Mother was so frugal that she only owned two pairs of stockings and would alternate between them, it has emerged.
The surprising revelation was made in a 1946 letter by Marion Crawford, who was governess to Elizabeth II and Princess Margaret.
The Scottish born educator, who Elizabeth affectionately referred to as 'Crawfie', served with the Royal Household from 1932 to 1947.
Crawford disclosed the Queen Mother's unflashy nature in a letter to Colonel Robert Wynn-Hughes, who swapped the military for the stockings trade, on August 16, 1946
She wrote: "Dear Col. Hughes, Many thanks for changing the stockings.
"The others are a lovely shade. I am enclosing one that has laddered but I really do not think you can do anything with it. If you cannot, just throw it away, as I think they have worn exceptionally well.
"Her Majesty has been wearing her only two pair alternately, so I think it is very good for them to have lasted so long."
Stockings were rationed during World War Two and it appears the Queen Mother wanted to 'lead by example' and avoid preferential treatment.
A cache of dozens of letters by Crawford, including correspondence with Margaret, has emerged for sale for £5,000.
The collection also includes a 1946 letter by Margaret written at Balmoral.
The then 16 year-old informs Crawford of a nasty leg injury the Queen Mother suffered during a walk in the Ballater hills.
She discloses that her mother had a hole in her leg 'which would not stop bleeding' but she was on the mend after several days rest.
Margaret wrote: "There are two tragedies. There ain't any grouse and we went for a 9 mile walk across the hills the other day, and Mama went and fell into a turn and made a hole in her leg which won't stop bleeding. Such a bore.
"But secretly I think she's enjoying not seeing a soul and having a rest.
"We are having a few people to stay and they are beginning to arrive so I hope she'll be better soon.
"She got up today and came to lunch but she can't walk yet. Goodbye. P.T.O. Lots of love Margaret."
The collection, which also includes a ticket to the 1937 George VI Coronation, is going under the hammer at auctioneers Moore, Allen and Innocent, of Cirencester, Gloucs.
Col Hughes' wife Rosemary Hughes gave the letters to her long-time gardener to thank him for his hard work, who has passed them down to his daughter.
She brought them into the auction house which was filming an episode of the ITV show Dickinson's Real Deal due for broadcast at the end of the year.
Crawford reportedly fell out of favour with the Royals after releasing the book 'The Little Princesses', which told the story of her time with the Royals, in 1950.
Neither the Queen nor any other member of the Royal Family are said to have spoken to her again. She died in 1988 aged 78 in Aberdeen.
Philip Allwood, senior partner at Moore, Allen and Innocent, said: "Marion Crawford was governess to Elizabeth and Margaret and she later wrote the first 'Royal expose' which saw her shunned by them.
"It is a one of a kind collection covering a vast array of subjects including day to day life within the Royal household and intimate letters from "Crawfie" to Robert.
"World War Two meant there was rationing for items like stockings and the Queen Mother obviously wanted to lead by example in that regard.
"One imagines Queen Victoria had dozens of pairs, although they were not in war time."
The Queen Mother died aged 101 in 2002. The sale takes place on July 5.
