There are a lot of theories about this, but no one can know for sure. However, Ellen Spertus has a wonderful paper, Why Are There So Few Female Computer Scientists? that will explain some of the cultural phenomena that might be a cause. Also, please read Val Henson's HOWTO Encourage Women in Linux.
If it pertains to women in Debian, it's probably on topic. That said, we're not trying to recreate debian-user, debian-mentors, or debian-devel. The list is primarily for discussing Debian Women related projects and collaboration.
For people that have never been on IRC before, you should first install an IRC client. Popular Linux clients available in Debian are HexChat, Pidgin and irssi. Once installed, connect to irc.debian.org and /join #debian-women. For more general IRC information, read the IRC FAQ.