Meet the Fokkens (2011)

Sisters doing it for themselves in Amsterdam's Red Light District. Louise and Martine Fokkens are identical twins. For over fifty years they were working as prostitutes. They freed themselves from the control of their pimps, ran their own brothel, and set up the first informal trade union for prostitutes. They are familiar faces in Amsterdam's Red Light District, but soon they will bid their farewells. The Ladies Fokkens is a portrait of these remarkable women, as well as a history of the Red Light District over the past fifty years.

Source: TMDb