Appearing on the Internet? Consider the wiki entry for Obama. That states that Obama's parents were married on Feb. 2, 1961. That was 6 months before he claims to have been born.
I realize that wiki is a biased source, but I believe that it truly reflects reality as Obama WANTS it to appear. Hence, it is "official".
If those dates are accurate, then you have to determine whether Michelle was referring to Obama's parents' marital status at conception, birth, or both. I can't answer that, it's above my pay grade.