[1][2] Delphine Lemaître showed a pronounced inclination for work from an early age and her unhappy marriage to Philippe Lemaitre[2] caused her to find solace in botany, specifically the study of flowers.
After devoting herself to botany, she began indulging her taste for French antiquities and published work in the Revue de Rouen and the Bulletin Monumental with investigations into the smallest details and complete descriptions of her subjects.
Her research on the chapel and fountain of the Trinity at Ézy-sur-Eure drew attention to clues of Celtic antiquity, as did her descriptions of the Castle of La Court, at Saint-Philbert-sur-Risle, on the residence of the Château de Pontchartrain, the Choiseul-Gouffier and the Montpoignant.
[2] The most enduring work left by Lemaître is her History of the Town and Castle of Dreux,[3][4] about which writer Amélie Bosquet said that it "must place its author in the first rank among those erudite minds to whom it belongs to clear the thorny field of our local antiquities.
She had already published several quality articles on this subject in the Bulletin Monumental as well as other notices about Montfort, Appeville, Brestot, and mainly on the stained glass windows of the church of Saint-Ouen in Pont-Audemer, when she died on 10 June 1863 in Illeville-sur-Montfort (Eure).