Ernestine Louise Potowski was born into a well-to-do Jewish family in Piotrków Trybunalski, Poland. Her father was a rabbi, providing her with a solid education in Hebrew and religious texts. However, she began questioning religious dogma early in life, demonstrating a strong independent spirit and a penchant for critical thinking.

Upon her mother's death, Ernestine's father, without her consent, betrothed her to a friend. To prevent the marriage, she invoked Polish law, arguing that she was entitled to her mother's inheritance and that she would use it to support herself. She won the case in court, demonstrating her early commitment to gender equality and her courage to challenge patriarchal norms.