I have a writing deadline or I'd spend more time on this issue--consider this a placeholder for now with several interesting links on the subject of gender parity in sci fi and fantasy writing and an encouragement--as in Nicola's Russ Pledge post--to add women's names whenever you see a "Best of" Sci Fi or Fantasy list seeking nominations. :)
Some of the links below give some names and in case you missed them, may lead you to some great books.
http://asknicola.blogspot.com/2011/06/taking-russ-pledge.html http://ask.metafilter.com/83126/Women-writing-SciFi-Your-Picks http://asknicola.blogspot.com/2011/05/shocking-uk-sf-favourites-score-men-500.html http://www.guardian.co.uk/books/booksblog/2011/may/31/women-science-fiction-writers?CMP=twt_gu http://www.guardian.co.uk/books/booksblog/2011/apr/18/game-of-thrones-girls-fantasy