It is quite possible, as the New Testament says that Jesus was her first-born. James, the brother of the Lord, was in fact, the brother of Jesus, and the first leader of the Church in Jerusalem.
There are Holy Grail traditions which centre around Sarah, the youngest sister of Jesus.
Anglican Catholic Answer.
The Ecumenical Councils referred to Mary as the
1, Mother of God!
2, Ever Virgin, as well as
Spotless and Immaculate.
This latter was at the Seventh Council and doesn't refer to the Immaculate Conception,It was thought that she was preserved from sin after the birth of Christ .
All these Councils were accepted by the Anglican Church! So for Anglicans, Orthodox and Romans it is looked on as a no answer!