In a letter written to a friend after the young Queen Victoria had announced her engagement to Albert, Nightingale that said she was too young for marriage.
"I wish she would have waited,'' she wrote in the eight-page letter of December 1840 to a Miss Strutt.
"We have been hearing a good deal lately of the virtues of the King Consort our 'beauteous Majesty' has taken to herself - from one of the grooms- in-waiting.
"So well-bred, so handsome, so simple, even according to English notions, and though both of them are 'o'er young to marry yet' it seems that she could not have chosen better.
"I wish however that she would have waited - but there was a certain tender sorrow at parting which betokened her to be really fond of him.''
Queen Victoria married her cousin, Prince Albert of Saxe-Coburg-Gotha, in 1840, when she was 21. Felix Pryor, manuscripts specialist for Phillips the auctioneers, said that Nightingale came from an affluent bourgeois family and that she had been presented at court.
"The letter indicates she is being faintly facetious,'' he said.
"She was a member of the upper classes and her family was very rich, while at the same time being advanced thinkers.
"Coming from this very privileged background, she had been introduced to Queen Victoria. One doesn't often think of Florence Nightingale as being the equivalent of a deb.''
Elsewhere in the letter, Nightingale tells her friend of the refurbishment of Embley, in Hampshire, one of two family homes.
"We are more and more pleased with Embley, now it is finished, notwithstanding the usual number of unprecedented delays, made by Mr Pratt of Bond Street. Our fatted pig should be killed if you would but come and see us.''
Both that letter and another written in 1881 will be auctioned at Phillips next Thursday with a pre-sale estimate of around pounds 400.