So, here the new graph updated to February 2013.
The necessary caveat is that is not easy (at least for me) to tell the gender just based on first names, so the actual numbers may be higher.
In addition, you should be warned that there are some contributions not easily traceable: it's the case of translators, graphic artists and documentation writers, as well as event organizers.
For instance, Beatrice Torracca doesn't appear in these stats, and she is the co-coordinator of the Italian translation team and a long term Debian (and free software in general) contributor. There was a proposal to better track non packaging contributors, but no news on that front yet (at least that I'm aware of).
"first uploads": via UDD (except for the first two cases that are from old changelogs)
DD and DM: taken from NM website
You can find the data used as well as the updated graph here.
- graph comparing male and female participation in Debian