Well. If she didn't know, how could you guys know? I'm talking about her birth. How you guys say she had to be born without sin too?
I doubt she remembers much of what happened before her birth.
Regardless, even if she had been aware of the uniqueness of her birth, that does not lead to an automatic conclusion that she and her betrothed would understand that she was to give birth without the benefit of a human father.
Can you explain how one leads to the other?
We explain it with hindsight, not foresight.
S