Wiki has a great listing of female writers and female detectives in fiction. First you should view the listing of female writers of detective fiction by clicking here: http://en.wikipedia.org/wiki/List_of_female_detective/mystery_writers The listing is arranged alphabetically and is quite long. There are some great information about the writers and a listing of the titles of their books. Some writers have more information than others of course. If you would like to add information on your favorite writer you might want to join the wiki community and add whatever you can that will help keep other readers informed.
They also have a listing of female detective characters. This list has female detective characters from novels, short stories, television, films and video games: http://en.wikipedia.org/wiki/List_of_female_detective_characters. Sadly, there are not a lot of pages linked to each of these characters and wiki really could use some help beefing up those pages. So, if you see your favorite character on the list and it doesn’t have a link with more information then gather your data on your character and type it in so that we can all enjoy it. Wiki is a great resource created by all of us for all of us.
We created a spreadsheet of female authors and sleuths along with some other information you might find useful. It is an on-going project and is not nearly finished but we thought you might enjoy looking it over and telling us what you think