I just finished reading a YA novel called SisterWife by Shelley Hrdlitschka. It's the story of a three young women linked to an extremely conservative Christian community that practices polygamy. In Unity, men are assigned multiple celestial wives by The Prophet. The group believes in eternal marriage that puts a whole new spin on the idea of forever. Girls, upon reaching the age of 15 are given in marriage.
Of the three young women, two are born and raised in Unity. One, Nannette, is steadfast and almost militant in her faith--her youth and immaturity making it hard for her to accept frailty or questioning in others. Especially the questioning of her sister Celeste who, a few days from 15, is wondering if there isn't much more to the world than being a plural wife and having children. In the mix is Taviana, a young street girl who was rescued by a member of the community and has found a way to reinvent herself and become more than she ever was in the "real" world.
The ending has proven to be controversial among others I know who've read the book. I admit to being undecided as to how I feel about it, but it was worth the read.