The history is short, well documented, and rather less romantic than the decks suggest.
Playing cards reached Europe from the Islamic world in the late fourteenth century. Divinatory use is not attested for another three hundred years and appears in eighteenth-century France, where Etteilla, Jean-Baptiste Alliette, writing his surname backwards, published on cartomancy from the 1770s and became the first professional card reader to make a living from books about it. He worked first with the piquet pack and then with a tarot of his own design.
Marie Anne Lenormand was a Parisian cartomancer of the Napoleonic era, celebrated, self-publicising, and reputed to have read for Josephine and for revolutionary figures. She did not design the deck that bears her name. The Petit Lenormand descends from a German parlour game, Das Spiel der Hoffnung, the Game of Hope, published by Johann Kaspar Hechtel in Nuremberg in 1799, whose thirty-six illustrated cards were laid out as a race track for a board game. After Lenormand's death in 1843 a publisher attached her name to a version of it, and the association has held ever since.
So the deck is a board game renamed for a fortune teller who never used it, which is a fair example of how these attributions generally work and is not a reason to think less of the reading system built on it.
Lenormand practice remained strong in Germany, Austria, the Netherlands, Brazil and Russia through the twentieth century while being almost unknown in the English-speaking world, and its arrival in English-language cartomancy is a development of the last twenty years or so. That is why English Lenormand literature is thin compared with the tarot literature, and why several competing English meaning-systems are currently in circulation without a settled standard.