Her father's lineage traces back to Loffenau, Germany, from where her second great-grandfather, Gottfried Streeb, immigrated to the United States, and where one of her ancestors served as mayor (the surname was later changed to "Streep").
Línia jej otca siaha do Loffenau, Nemecko, odkiaľ pochádza jej prastarý otec, Gottfried Streeb, ktorý emigroval do Spojených štátov, a kde jeden z jej predkov slúžil ako starosta (priezvisko bolo neskôr zmenené na „Streep“).