Marsha is the author of nine YA books and a wry, witty speaker who keeps her audiences enrapt, challenging notions about what teens read and why they read. She volunteers her time to work with teens in literacy programs, prisons, and social programs, staying on top of their interests, language, and perceptions. Librarians and educators have evaluated her presentations as "informative and entertaining," "really clued in to teens and their lives," and "someone I'd turn to in a heartbeat for her insights into books and writing."

Marsha is an associate professor in Hamline University's MFA program in writing for children and young adults. She speaks at conferences and writing programs around the country.