Women are coming to play a bigger role in some radical secular Baathist insurgent groups. It's believed that women have even taken the lead in organizing a few insurgent cells. While the most effective use of women by the terrorists would be to facilitate communications among the increasingly isolated insurgent cells, and to collect intelligence, it appears that more women are being recruited for suicide operations. As has happened elsewhere (Israel and Chechnya), the women are often relatives of men who have been killed by the enely ( conducting suicide attacks or otherwise). Sometimes the women are willing to carry out a suicide attack because of this, but often the women are coerced. A widow does not have a lot of options in Iraq, or the Middle East in general.
Normally, al Qaeda subscribes to religious customs that severely limit the activities and opportunities for women. But in this case, women are simply the most talented people available. Iraqi women are more likely to get a college education than anywhere else in the Middle East, and families often put their talented women to good use. Saddam Hussein used several female scientists and engineers to develop weapons of mass destruction, and critical military systems. Most of these women are still around, and unemployed because of their previous service for Saddam. Many of these women believe in the idea of the Sunni Arab minority ruling Iraq, and are willing to use their talents, and risk their lives, to make that happen.