After graduating from Boston University School of Law, Terrell worked as a litigator for ten years, practicing in New York City at Skadden, Arps, Slate, Meagher & Flom, and Morrison & Foerster.

Terrell published her first novel, The Chrysalis, in 2007,[5] after which she left her work as a litigator and began writing full time.

"[6] Later in her career, Terrell began writing about women who were often overshadowed by the men in their lives, including Mileva Marić (The Other Einstein, 2016), Hedy Lamarr (The Only Woman in the Room, 2019), Clementine Churchill (Lady Clementine, 2020), Belle da Costa Greene (The Personal Librarian, 2021), and Rosalind Franklin (Her Hidden Genius, 2022).

The Only Woman in the Room, published in 2019 by Sourcebooks Landmark, is a fictionalized biography of Hedy Lamarr.

[8] The Personal Librarian, co-authored by Victoria Christopher Murray and published in 2021 by Berkley Books, is a fictionalized biography of Belle da Costa Greene's life as the personal librarian to J. P. Morgan and the first director of the Morgan Library & Museum.