She also fears that her only son Ben Henrickson believes in polygamy and asks her mother to take him and introduce him to non-polygamist Mormons, hoping to erase his interest in plural marriage.

She also tells Bill that she rejects the idea of ever having a fourth wife, and to appease her, he offers her a board membership in his new company, Weber Gaming.

In Episode 30 the family takes a cross-country trip to discover their Mormon roots at Hill Cumorah, NY at Bill's urging.

Barb discovers Nicki's birth control pack in the motel bathroom but she assumes they are Sarah's, not knowing her oldest daughter is already pregnant.

Season Four sees Barb taking a leadership role at the casino that the family has opened on a Blackfoot Indian reservation, but coming into conflict with Native American customs and culture.

She at first opposes daughter Sarah's choice of a secular Justice of the Peace marriage, worried that she and her husband will not reunite in eternity.

Barb seeks out Mormon and non-Mormon feminist scholars to support her, causing her mother and sister to express their concern over her new theological ideas.

Events come to a head when Barb decides to be baptized in a Latter Day Saint denomination that allows women to hold the priesthood but rejects polygamy.

A flash forward in the series's closing moments reveals that Barb is now the leader of the only Mormon fundamentalist church that practices both polygamy and female priesthood.