James & Jude I believe were depicted as "brothers" as in fellow Christians are "Brothers and Sisters".
But not ACTUAL "brothers" or "half brothers".
Otherwise I think that would negate the term "Bride ever Virgin". I mean obviously the Theotokos, the mother of God, would not be a virgin right now if she had other children. Also if we would consider Jude & James to have the same blood as Jesus, that can open up a huge can of worms of possible heretical thought.
James and Jude are the children of Joseph, who was a widower when he was betrothed to the Blessed Mother. In the eyes of the Law and of those who knew them, James, Jude and the rest of Joseph's children were the siblings of our Lord and, therefore, are named, as such.