If Mary were a sensible girl, she'd have said, "no."
The television show The Big Bang Theory revolves around the on again, off again romance between Leonard and Penny. In the episode The Recombination Hypothesis, Leonard asks Penny out again, leading to a series of comic relationship blunders. But at the climax of the episode it is revealed that, beginning at the point where Leonard asks Penny out, everything has just been Leonard's projection of how such an invitation would likely lead to disaster.
Even so, Leonard walks across to Penny's apartment and asks her out to dinner.
Penny asks, "Have you thought this through?"
And Leonard responds, "Yes, and I think we should go anyway."
Mary may not have been a prudent girl, but she was not a foolish girl. She understood the risk she would be taking very clearly. But she was a faithful girl. If we had been there to ask, "Have you thought this through?" she would have responded "Yes, and be it unto me according to the angel's word anyway."
And thanks be to God for that.