Oh, ok. I see how you are. Hold that thought a minute.
"Mary knew the sign of the messiah......."
And how exactly do you know this?
"Isaiah 7:14 Therefore the Lord himself shall give you a sign; Behold, a virgin shall conceive, and bear a son, and shall call his name Immanuel."
Well, unfortunately for you, this passage only proves that Isaiah knew the sign of the messiah. So, unless you can meet your own burden of proof, a scriptural passage stating explicitly that Mary knew the sign, I'll take it your assertion is based on nothing but speculation.
Fair is fair, FC. If you are going to insist on a particular standard, the least you can do is hold yourself to it.
Are you now claiming that Mary was not a good Jew and did not know the Scriptures?