I learned about Maurice Ehlinger (1896-1981) on the blog Novel Activist via Art Controversies. Ehlinger was an award winning french painter whose aesthetic and muse, like Serge Marshennikov and Balthus, was the nymphet.
Ehlinger was born in Saint-Die-des-Vosges, but he eventually settled in Paris where he was accepted at the famous l'atelier de Flameng. Subsequently, Ehlinger earned money as an art instructor by day, which allowed him to paint in his studio by night.
Ehlinger's nude nymphets can be found in a number of French museums including the Museum of Pierre-Noël Saint-Die-des-Vosges