Complex sentence: She was one of the early church "elite", having married two separate powerful men in polygamous marriages as well as being the sister of David Fullmer and John S. Fullmer, both members of the Council of Fifty.
Split into simpler sentences: She was one of the early church "elite", having married two separate powerful men in polygamous marriages. Brothers David Fullmer and John S. Fullmer were both eventual members of the Council of Fifty.