Edwards began writing romances in 1982 and released her 100th novel, Savage Skies, on August 28, 2007. Although her earlier books were classic historical romances, the vast majority of her novels involve Native American tribes. Edwards's grandmother was a full-blooded Cheyenne. eReader.com: Author: Cassie Edwards Her first 99 books sold a combined 10 million copies as of August 2007, with her more recent novels averaging sales of 250,000–350,000 copies.
Edwards has won the Romantic Times Lifetime Achievement Award and the Romantic Times Reviewer's Choice Award, as well as being named one of Affaire de Coeur's top ten favorite romance writers. Edwards has a reputation for meticulously researching the proper anthropological backgrounds of each tribe she writes about.
Edwards and her husband Charles, a retired high school biology teacher, have been married for over 50 years. They have two sons, Charles and Brian, and three grandchildren. The family lived in St. Louis, Missouri for over thirty years, but now reside in Mattoon, Illinois.
On 7 January 2008, the romance-novel review blog Smart Bitches, Trashy Books accused Edwards of widespread plagiarism after finding multiple passages in her novels that appeared to be directly taken from various works by other authors, including novels, poems, reference books, and websites about Native American history and culture. Many of the passages came from old references, many without copyright or expired copyright. One of Edwards' publishers, Signet, initially defended the passages in question as fair use rather than copyright infringement.
Nora Roberts, herself a victim of plagairism, joined the outcry. Two days later, Signet announced that they would be reviewing all of Edwards' books that they published to determine whether plagiarism had occurred, and, in April 2008, Signet stopped publishing Edwards' books "due to irreconcilable editorial differences." In an interview, Edwards said that she did not know she was supposed to credit sources, and her husband stated that Edwards gained ideas from her reference works but did not "lift passages".