Born in Horsens on 10 March 1852, Emmy Marie Caroline Thornam was the daughter of the high-school teacher Ludvig Thornam (1819–1879) and his wife Anine Charlotte Frederikke née Norup (1824–1895). She was raised on the Hanstegaard estate in a well-to-do environment. Interested in drawing from an early age, Thornam was given an excellent education which included the Technical School in Horsens and Vilhelm Kyhn's Art School for Women (Tegneskole for Kvinder) from 1873 to 1875. She was later a pupil of the Danish flower painter Oluf August Hermansen and, while in Paris, of the French flower painter Pierre Bourgogne. Together with her sister, she made study trips to Paris (1887–1888) and Italy (1893–1894). In 1901, she traveled to Corsica, Italy and Algeria.
