From #30
Book of James, or PROTEVANGELIUM Origen mentions the Book of James (and the Gospel of Peter) as stating that the ' brethren of the Lord' were sons of Joseph by a former wife.
That's not to say either above are completely accurate, but it is a source of information on the matter apparently from the 2nd century, and carries for more weight than "some opinion", by someone who doesn't care enough even to research the matter further, and that same someone who would dismisses evidence without a thought.
There may even be other substantiating documents out there, as to the relative ages of Mary and Joseph.
A sound hermeneutic is that unless an exception to the norm is stated, then the norm is to be accepted. The Holy Spirit characteristically records extraordinary aspects of even far less persons in Scripture, from great age (Methuselah), to excess size, fingers (Goliath), hair (Esau) strength (Samson), prolonged celibacy (Anna), diet (John the Baptist), to the supernatural transport of Phillip, the singleness of Paul and Barnabas, and the uncharacteristic duplicity of Peter, and the surpassing labor and suffering of Paul, to the virgin birth of Christ and Him being single and sinless.
But while stating her virgin status before Christ was born, nowhere is Mary stated to be a perpetual virgin.
For while the Spirit specifies that Joseph "knew her not till she had brought forth her firstborn son: and he called his name JESUS," (Matthew 1:25) firstborn normally is used with distinction from latter born, and the Greek for "till" almost always indicates a terminus and change or allowing for it.
In addition, marriage is described from the beginning as sexual cleaving, (Gn. 2:24; Mt. 19:3-5) and there is only one possible exception to that, which was that of a very infirm old man, David, with Bathsheba. (1Kg. 1)
Furthermore, a Messianic prophecy states "I am become a stranger unto my brethren, and an alien unto my mother's children," (Psalms 69:8) which corresponds to His brethren therefore said unto him, Depart hence, and go into Judæa, that thy disciples also may see the works that thou doest. For there is no man that doeth any thing in secret, and he himself seeketh to be known openly. If thou do these things, shew thyself to the world. For neither did his brethren believe in him. (John 7:3-5)
Here again, there is no warrant or need for reading an exception to the norm, that brethren meant other children of Mary.
And since this would require the assent of her head, then if perpetual Marian virginity (PMV) was the case, and since this would normally be more difficult for the male, then Joseph would deserve more honor.