In the summer of 1939, Sterne and her husband returned to Bucharest from France for the last time. With the outbreak of World War II in September, the couple began to prepare to leave Europe for the United States. However, Sterne did not accompany her husband in the spring of 1940 when Fritz Stern left for New York. Instead, she remained in Bucharest with her family, where in January 1941 she was witness to the Bucharest pogrom and increasing political unrest. After trying for several months to acquire all the necessary visas to leave Romania for the U.S., Sterne finally departed Lisbon for New York aboard the "S.S.Excambion" on October 17, 1941.