Often enough on FR and elsewhere and the evidence I posted from Protestant sources is conclusive if it isn't let me know how it isn't.
James is referred to the brother of Christ in more than one place in Scriptures. We can take one conclusion away from all these accounts. They were surely raised together in the same house and Mary was the mother whether by proxy or birth.
So; it COULD be real siblings or it COULD be cousins; eh?
Well then; let’s DEFINITELY ignore the first and cling onto the second; for IT surely fulfills the need of Rome to keep Mary a virgin!