The appeal to the ECFs does not work as they are all over the board on a number of topics. They're only consistency is their inconsistency.
Per Dr Robert Schihl the ECFs (at least some) from at least the fourth century spoke of Mary as having remained a virgin. He specifically lists
Athanasius: 293-373;
Epiphanius: 315?-403;
Jerome: 345-419;
Augustine: 354-430:
Cyril 376-44
.https://www.ewtn.com/faith/teachings/maryc2.htm
So unless this catholic apologists has his facts wrong the earliest ECF to believe this was around the third century.
We know false teachings were already creeping into the early church as evidenced by Paul's and John's writings.
With Luke being a doctor, and being as careful as he was in his research for his writings, I think he would have understood the difference between the use of brothers and sisters in the general sense vs as in the family sense.
The Greek and the context of the New Testament along with the testimony of Paul tell us Joseph and Mary had other children.
To continue to believe otherwise shows a rejection of the Word in favor of "Tradition".
For the catholic to continue to insist the Word doesn't say what it says means the Word has to be twisted to make it fit roman catholic theology.
As an example: Finally, there is the doctrine that Mary remained a virgin throughout the rest of her life. In fact, only an original, lifelong commitment on Mary's part to preserve her virginity makes sense of the words that she spoke to the angel Gabriel. After being told by the angel that she would "conceive in her womb and bear a son," Mary replied, "How can this be, since I have no husband?" (Lk 1:34). Catholic Biblical scholar Dr. Scott Hahn explains:
Now this would be an odd question if Mary had planned to have normal marital relations with her husband. The angel told her only that she would conceive a son, which is a commonplace event in marriage. ... Mary should have known exactly "how this shall be." It would happen in the normal course of nature.http://www.thedivinemercy.org/news/Part-7-Mary-Ever-Virgin-6371
No, the question is not odd. Mary and Joseph had not engaged in intercourse at this point. She knew about babies and she knew she and Joseph, or her and anyone else for that matter, had not engaged in intercourse.
That's why she's wanting to know how this was going to happen.
Her question makes perfect sense if you read the verse in Luke in context. The angel tells her she's going to have a baby and she knows she hasn't engaged in sex. So how can this be???
There is nothing in this exchange to indicate she was planning on remaining a virgin. It's one of the most convoluted twists of Scripture I've seen.
But Roman Catholicism is not Christianity, so any twist of The Word is allowed so long as it supports the dictates of the magicsteeringthem. The Momrons do the same thing with Scripture, and for the same reasons.