She was initially known for her adaptations of the popular manga series After School Nightmare (nominated for a 2007 Will Eisner Award), Black Sun, Silver Moon, Her Majesty's Dog, and 07-Ghost.
In addition to her work adapting manga, she assisted in editing or producing many other titles, the Go!
In 2013, she co-authored The Silver Dream with Michael Reaves and Neil Gaiman.
Most recently, she authored the graphic novel Mirror Moon (2021), set in the universe of The Nightmare Before Christmas.
In addition to her work as a writer, Mallory has dabbled in voice- and screen-acting, appearing in the anime series NieA 7 (credited as Mowi Reaves) and the Star Trek: The New Voyages episode "World Enough and Time".