What is the incentive for female suicide bommers?

Today 2 women blew themselves up in a suicide attack on a pet market. In this case the women were supposedly mentally disabled, but there seems to have been a rash of female suicide attack recently. This got me to thinking, what is the incentive for women to do this type of thing. The men of course have the glory of Allah, as well as the promise of 70 virgins when they get to heaven. Women can, of course, glorify Allah by doing this sort of thing, but is there an equivalent promise to the 70 virgins for the women? I'm being serious here, no disrespect intended at all. I doubt any of our readers know the answer to this question, but it does seem vexing to me. Thoughts....?