Constance was born in Brooklyn, New York, where her mother's family landed after leaving Belfast, Northern Ireland. Raised in the New York area, she grew up in the home of great readers, and became one herself. Writing detective fiction as a nine-year-old, she peppered the pages with snappy dialogue.

Constance's fiction incorporates her love of origins as well as journeys taken at a walking pace. The Irish family stories found a lifelong home in Constance, and formed her as a writer. She creates characters who feel dislocation and regret but have the resilience common to all survivors.

She lives with her wife and their dog in the foothills of the Berkshires. Both women were raised in the city, but they love almost everything about country life.