I'll go out on a limb here and wager that I am the only person in this thread who actually has firsthand experience with this subject. The converts I know are in fact mostly women, none of whom converted for the purposes of marriage. If I were to guess at a reason, it would be that women tend to find themselves marginalized in society to a much greater extent than men, which might lead one to seek out religion.
From your personal experience, are female converts to Islam (or male for that matter) generally formerly non-religious, i.e. not converts from other religions?
Yes. I don't know of anyone who seriously practiced another religion before converting, and I suspect that that is much rarer in general.
