This is very helpful and comprehensive study of the historical, present and possibly future status of men and women in the church.
The author has a unique style which I found appealing and yet frustrating at the same time. Appealing, because as an egalitarian she is totally friendly, warm and most definitely NOT antagonistic towards the "other side" (complementarians). She is also humble, personable and easy to read.
(If you are already confused, egalitarianism is the view that God calls believers to roles and ministries in the church without regard to gender, and that male headship is not biblically-ordained either in the home or in the Church. Complementarians believe the opposite).
On the other hand Sumner is frustrating because she does hop about a lot! She realizes this and makes no excuses. But if you are expecting linearly developed arguments from A to B to C, you may be in for a surprise from time to time, as you go from A to S to Z and then to B before shooting off to X and Y before landing on C.
However, persevere and you will come across some extremely well-thought and at times creatively original ideas about the place of men and women in the church. And not only in the church - in marriage too. The Christian husband may be interested when Sumner writes that "nowhere in scripture is a husband told to lead his wife", or that "the words lead, leader, servant leader and spiritual leader cannot be found in any Bible passage on marriage."
Sumner concludes that "men and women should be leading the Christian community ... not to turn the church upside-down, but to turn the church right side up." She makes a convincing argument that deserves to be taken extremely seriously.