Shauna Niequist's mom had spent almost all of her adult life being a pastor's wife, mother, and homemaker. She excelled in all of these roles. But 17 years in, she walked into a counselor's office and said, "I don't know who I am anymore. Something has to change." Through counseling, friendships, and prayer, says Niequist, her mother unearthed the gifts and passions that had drawn her to a social work degree. "I found my voice in my 40s and my vocation in my 50s..." Betty Friedan would have been proud. Surprised, too, perhaps, to see her ideas—dissected and debated for...