The daughter of Polish Jews, Shtettin had a strict Orthodox Jewish upbringing in London. She began her theatrical career as a teenager in the chorus of Israel Grodner's London troupe in the mid-1880s, eventually getting small parts, and joining Adler's troupe when the Grodners went to Paris. Jacob Adler, then a widower, quickly took a liking to her. At this time, he was already involved with Jenny ("Jennya") Kaiser, whom he had become romantically involved with while his first wife, Sonya, was still alive, and by whom he had had a son, Charles.