Alexandrine-Jeanne Le Normant d'Étiolles (10 August 1744 – 15 June 1754) was born during the "Scenes of Metz", in which the public was scandalised to learn of the adultery of her stepfather-to-be, Louis XV of France.
She was the daughter of Madame de Pompadour, Louis XV's celebrated maîtresse-en-titre.
Her biological father was Charles-Guillaume Le Normant d'Étiolles, husband of the future marquise de Pompadour, who was not yet Louis XV's mistress at the birth of her daughter. Alexandrine was nicknamed "Fanfan" by her family. She is remarked to have been very thin throughout her very short life, but healthy.
Her mother became mistress of Louis XV in 1745. Louis arranged the legal separation of her parents and served as her unofficial stepfather for the rest of her life.
At the age of six, Fanfan was put in the convent of the Assumption in the rue Saint-Honoré in Paris, a convent for girls of the nobility that served as her finishing school.
She was betrothed at age eight to the Duke of Picquigny, son of the Duke of Chaulnes, with the agreement that she would marry Picquigny at the age of twelve.
François Poisson, Mme de Pompadour's father, doted on his granddaughter, whom he loved dearly. Madame de Pompadour even wrote, "Why must grandpapas always spoil their grandchildren?", referring to Poisson's love for Fanfan.
On 4 June 1754, Fanfan took ill at the convent of the Assumption. Charles-Guillaume Le Normant d'Étiolles rushed to her side, but Madame de Pompadour, who was at Versailles, could not come. Upon learning of her illness, Louis XV sent two of his own doctors to her side, but the child had already died of acute peritonitis when they arrived. Fanfan was not yet ten years old.
Her grandfather, François Poisson, died eleven days later, on 25 June 1754, devastated by his dear Fanfan's death. Her mother reportedly never recovered from the loss of her daughter and father within a few days.