Complex sentence: Late in her life, while traveling extensively to speak, she based herself in Battle Creek, then headquarters for the Seventh-day Adventist Church and until her death there she was closely associated with many early Adventist leaders.
Split into simpler sentences: Late in her life, while traveling extensively to speak, she based herself in Battle Creek, then headquarters for the Seventh-day Adventist Church. Until her death in Battle Creek, she was closely associated with many early Adventist leaders.