Susan began her journalism career at The Miami Herald, later holding internships at The New York Times. She went on to spend several years as a staff writer at Maclean’s, specializing in long-form and investigative reporting. As a freelance journalist, her work has appeared in The Sunday Times Magazine, Glamour, Marie Claire, The Guardian, and The Walrus.

Described by Quill & Quire as a pioneer in trauma-informed reporting, Susan is the author of award-winning creative non-fiction for adult and young adult readers. Her books have been published in more than thirty countries and recognized with distinctions including a Kirkus Best YA/Memoir and multiple Ontario Library Association Red Maple Awards.

Her storytelling extends to documentary film. She served as researcher and narrator for The Nanny Business, directed by Academy Award–nominated filmmaker Shelley Saywell, a project that grew from Susan’s investigative work on Canada’s Live-In Caregiver Program and the global migration of women for domestic labour. She is currently leading the film adaptations of two of her books.

Susan and her daughter, Charlotte Lindsay Marron—a producer, finance major, and actor—are the co-founders of Full Cup Productions Ltd., a media company devoted to stories that illuminate the unseen and challenge accepted narratives. Guided by the belief that truth, when revealed with care, has the power to connect and transform, Full Cup produces socially engaged, thought-provoking scripted and unscripted content across genres.

In 2025, Susan and Charlotte were awarded the Realscreen Propelle: A+E Factual Development Accelerator at the Realscreen Summit in Miami, securing development deals with A&E and Lifetime.