Interestingly the gender gap is much smaller this time around than in 2008 and married women in particular think Obamacare is not championing the cause of modern women.
Bottomline, the "war on women" is a fiction invented by Team Obama and while the populace in general has not bought into, his followers have.
I think the reasoning is a lot simpler than that married women are more concerned about the economy and family health care whereas single women care about social issues.
Single women are going to be younger and younger people have always tended to be more progressive whereas older people become more conservative. Breaking down any further than that is mostly conjecture, imo.