Complex sentence: She developed an academic interest in the occult through her association with the Theosophical Society beginning around 1887 and, as a freethinker, was elected Secretary of the Philadelphia chapter of the American Secular Union in 1889.
Split into simpler sentences: She developed an academic interest in the occult through her association with the Theosophical Society beginning around 1887. As a freethinker, she was elected Secretary of the Philadelphia chapter of the American Secular Union in 1889.