A professional freelance author who began her career in publishing as an avid D&D player, Lassieur worked for thirteen years in the publishing industry as an editor for magazines such as Disney Adventures and Highlights for Children. She's edited game products for TSR, West End Games, and Sierra Online. In addition, she has more than two dozen nonfiction children's books to her credit and has contributed to such magazines as National Geographic World and Scholastic News. Lassieur lives and works in Eastern Pennsylvania.