Sacred Scripture does not provide many details about the life of St. Joseph. Turning to tradition, we gain the following perspective. First, it is certain by matter of the dogma of Mary’s perpetual virginity (already defined by solemn council in the early Church) that her marriage to St. Joseph was never consummated. Thus, it is clear that Jesus would have had no blood brothers or sisters. It is possible that St. Joseph was older and had been married prior to his betrothal to Mary. Thus, he could have had other children who would be half-siblings of Jesus. However, the references to brothers and sisters of Jesus in Sacred Scripture must be understood in the cultural context. Even to this day, in the Middle East it is quite common to refer to cousins and even more distant relatives as brothers or sisters. The notion of family is much more broad than the Anglo-Saxon model and the use of language is subsequently more general. Jesus’ parting gift on the Cross of giving Mary to St. John (“Behold your mother” and “behold your son”) is fairly strong evidence that there were no siblings at all (half or otherwise). Those siblings would have automatically been responsible for Mary’s welfare rather than what actually occurred when St. John “took her into his home from day.” I hope that this sheds some light on your question. God bless you!
Rev. Joseph R. Johnson
Archdiocese of Saint Paul and Minneapolis
Tel. 651-291-4401 Fax 651-290-1637