From an early age, her father used her as a model for his many illustrations in children's books published by the editor and publisher Pierre-Jules Hetzel, especially the Mlle Lili series including La journée de Mlle Lili (1862) and Voyage de découvertes de Mlle Lili (1866).
[1] Her mother died when she was 13 but it was only when she was 16 that she moved to Denmark where she lived in the Copenhagen neighborhood of Rosenvænget at home of the artist Thorald Læssøe (1816–1878), one of her father's best friends.
She returned to Paris to continue her studies, first under the traditional historicist Félix-Joseph Barrias (1879–1881) and then as a student of Alfred Stevens (1881–83) who had been influenced by Japanese art and Impressionism.
While in Paris, she became a friend of Sofie Holten, Suzette Skovgaard and Elise Konstantin-Hansen, who were also studying painting there.
[1] Frølich created mainly portraits in pastels but also painted still lifes and floral works in oils.