Osterman was born in Germany, though she and her family moved to the United States, settling in Baltimore when she was very young. In 1825, still in Baltimore, she married Joseph Osterman. Her brother, Leon Dyer, encouraged her husband to set up a business in Galveston in 1837 and a year later, Osterman followed him. She and her husband turned a small business run out of a tent into a large general store and an import-export business. They were among about 30 Jewish residents in Galveston at the time. The business was a great success and Joseph Osterman retired by 1842, selling the business to Osterman's brother, Isadore Dyer. The Ostermans built the first two story residence in Galveston, which later in 1921, became the headquarters of the YWCA. Osterman shared her recipe for dried meat b