Did Mary have biological children after Jesus?

[DaleCooper]

I never got the impression from the Bible that Mary was extremely young, or for that matter that Joseph was old, but that's a different issue. It should be noted that according to one of the gospels she was already betrothed to Joseph when the conception took place, so I don't see why she would've been younger than any other young woman entering her first marriage.

As for her having children after Jesus, it's pretty clear that Jesus had siblings, who would have to be younger if you believe in the virgin birth. Paul himself refers to James as being the brother of Jesus Christ in a context that doesn't seem to imply that he is talking about a spiritual brother. In fact, I think that line from Paul in Galatians is one of the best pieces of evidence for the historical existence of Jesus Christ.