Louise-Rose-Étiennette Gérard, known as Rosemonde Gérard (1871 – 1953) was a French poet and playwright. She was the wife of Edmond Rostand (1868–1918, author of Cyrano de Bergerac), and was a granddaughter of Étienne Maurice Gérard, who was a Marshal and a Prime Minister of France.
Étiennette Marie Périne de Villemomble, née Étiennette Le Marquis (1737–1806), was a French dancer and courtesan, the official royal mistress of Louis Philippe I, Duke of Orléans between 1759 and 1773. She was made 'dame de Villemomble' in 1767.
This name just looks very, very confusing. With my knowledge of French (about "Seconde" or "Première"), Étienne has always appeared feminine to me, even though I know it's a masculine name. Étiennette looks like it has two endings traditionally used in French feminine names: -enne and -ette, one right after the other.That's likely why this name has fallen out of use. (Though Étienne is still fairly common, go figure.)