In 2003, her novel Fire Logic, the first in her Elemental Logic series, won the Gaylactic Spectrum Award for "best novel"; in 2005 Earth Logic, the second in the series, won the same award. She teaches writing at the University of Massachusetts Boston and lives with Deb Mensinger. In 2004, Marks and Mensinger married in Massachusetts. In 2007 she was Guest of Honor at the WisCon science fiction convention.
The Elemental Logic series is set in the world of Shaftal. Some 35 years prior to the first book, Shaftal was invaded by an army of Sainnites who, in an attempt to eradicate the magic which might be used against them, killed all the elemental witches they could locate. However they failed to realise that magic is inherent in the Shaftali and children have been born since who can wield it. Furthermore, the Sainnites have become cut off from their homeland and are subject to constant guerilla action from the Shaftali. Among both the learned, peace-loving Shaftali and the warlike, spartan Sainnites, women and men are equals in all things, including military, and both queer and polyamorous/polygamous relationships are common and accepted.