In 1994, Bennion received a Dean's Scholarship Award for her ethnography, published by Oxford University Press, Women of Principle: Female Networking in Contemporary Mormon Polygyny.

In her first book, Women of Principle, she recorded the experiences of female converts in the Montana Allredite order, finding that many women are attracted to polygamy because of the socioeconomic support it offers, replacing a rather difficult life in the mainstream where their status as divorcees, single mothers, widows, and "unmarriageables" limited their access to good men and the economic and spiritual affirmation that comes from a community of worship.

Finally, Mormon fundamentalism balances the deprivations and difficulties of the lives of polygamous wives with a promise of an afterlife as queens and priestesses.

For her dissertation, she explored the factors contributing to female conversion patterns and investigating the intimacies between co-wives in the holy wedding ceremony which bonds women to each other and to one man.

Her examination of the atrocities following the Texas raid on the YFZ Ranch, where 460 children were removed from their homes is found in Cardell Jacobson's anthology and in her Mellen book.