Rosa Jaretzki was born in Posen on April 4, 1864, the daughter of Louis and Theresa Jaretzki.

Kurt Zarinzansky was born in Berlin on January 28, 1890, the son of the factory owner Siegmund Zarinzansky and his wife Rosa, née Jaretzki.

Ada Lea Rosa Löwenstein was born into a Jewish family in Oberhausen on October 16, 1911.