Fernanda Weiden has some ideas why not more women are involved in FLOSS.
Her article can be found at here and is followed by a whole set of reader comments.
Maybe it an issue of language but I don´t believe, as fernanda Weiden writes, that women have a "natural insecurity" that prevents them from participating in technology. It is more a gendered insecurity.
If you read Portuguese, it may be interesting to check out one of the projects mentioned by Weiden:
"Projeto Software Livre Mulheres: (“Women Free Software Project” - PSL Mulheres) in Brazil. PSL Mulheres works mainly on talking with other feminists/female groups to get them discussing about gender and digital divide and about how to use Free Software to solve that. It also works giving technical support to these organisations. Women in general has no access to technology. That's why they not get involved on it."