We recently purchased a publication from Internet Genealogy called "Tracing Female Ancestors, Volume 2." It is the second edition on this topic with additional strategies and resources for locating those difficult female ancestors. One article tells ways to use a website such as FamilySearch to look specifically for women. Other suggestions include a Google search, use of city directories, websites with digitized books, and locating church records.
The magazine will be available for club use next season, or you can find your own copy at one of the large book stores.