Yes, but the angel said “shall conceive”, indicating a future event. If someone said to me (even an angel) when I was that age, ‘you will have a child’, my first question would not be ‘how?’, but ‘when?’. (At this age it would be ‘how?’ but that’s a different story :-) )
Of course Mary knew how babies were made, so why did she know from this statement that this one would be made differently? There is nothing in what the angel says prior to her question that would indicate she would remain a virgin to have this child. He doesn’t tell her that she will be made pregnant by the Holy Spirit until after she asks.
Love,
O2
Perhaps there is hope! ... Remember Abram’s wife Sarai?