Rosika (Rose) and Jansci (Jenny) Deutsch, identical twins born 25 Oct 1892 in Hungary were likely Fitzgerald's inspirations for the "Girls in Yellow." They became Broadway entertainers known worldwide after immigrating the to U.S. in
Rosie and Jenny Dolly were born Rosika and Jansci Deutsch (I have also heard Roscizka and Janszieka) on October 25, 1892 in Hungary. They came to the United States in 1905. They also had a brother Eddie who performed as well. They began making the rounds as dancers and were appearing on stage to earn money. They were soon banned in New York for working underage, and so they took to touring.