Nedra Glover Tawwab wants people to know that positive changes in relationships are possible, even if those around you don’t want to revise their behavior. That’s what her new book, Drama Free: A Guide to Managing Unhealthy Family Relationships is about. The National Writers Series will host her at 7 p.m. on Friday, July 21 the City Opera House and via livestream. Her first book, Set Boundaries, Find Peace became an instant New York Times bestseller.