The name on her birth certificate is Theresa Josephine Barnum but for most of her life and on most later official documents she was known as Josephine, with Theresa as her middle name. It is thought that she was called Josephine because her parents had hoped for a son whom they could have named after her grandfather Joseph Ira Barnum. The family is not sure whether the change in name order was her idea or that of her parents. They believe that Charles and Ada did have a son but that he died very young. Josephine had no other full siblings but did have two half brothers, sons of her mother's first marriage.
Josephine Barnum married Ralph Brown. They had two children, Warren Barnum Brown and Arlene Muriel Brown.