Apparently a companion piece to this photo ("Vintage hand colored real photo postcard, circulated in 1911, divided back, published by Gustave Liersch & Co. (GLCo), Berlin, Germany. © Casas-RodrÃguez Collection, 2009. Some rights reserved.)
Found at Vintage Photography.
Addendum: The young model's name was Grete Reinwald (dozens of photos and some biographical information at the link).
Addendum: The young model's name was Grete Reinwald (dozens of photos and some biographical information at the link).