Scripture tells us that Jesus was her FIRSTBORN son, and since we know that those *ignorant sheepherders* can at least count, they would understand the difference between ONLY son and FIRSTBORN son.
YES!
Luke uses the word πρωτότοκον in describing Jesus.
The word conveys the following meaning:
4416 prōtótokos (from 4413 /prṓtos, "first, pre-eminent" and 5088 /tíktō, "bring forth") – properly, first in time (Mt 1:25; Lk 2:7); hence, pre-eminent (Col 1:15; Rev 1:5).
4416 /prōtótokos ("firstly") specifically refers to Christ as the first to experience glorification, i.e. at His resurrection (see Heb 12:23; Rev 1:5). For this (and countless other reasons) Jesus is "preeminent" (4416 /prōtótokos) – the unequivocal Sovereign over all creation (Col 1:16).
[4416 (prōtótokos) refers to "the first among others (who follow)" – as with the preeminent, glorified Christ, the eternal Logos who possesses self-existent life (Jn 5:26).]
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Now contrast this with John's description of Jesus being the only begotten Son of God.
μονογενῆ is the word he uses.
It conveys the following:
3439 monogenḗs (from 3411 /misthōtós, "one-and-only" and 1085 /génos, "offspring, stock") – properly, one-and-only; "one of a kind" – literally, "one (monos) of a class, genos" (the only of its kind).
Luke used this word also in 7:12, 8:42 and 9:38 to note the only child of others.
He did not use it in relation to Jesus.
This is significant in that Luke was a doctor....a man trained in the medical field. He would know if a woman had more than one child.
Further, Luke tells us he specifically "....investigated everything carefully from the beginning, to write it out for you in consecutive order, most excellent Theophilus; 4so that you may know the exact truth about the things you have been taught." Luke 1:3 NASB
Luke notes in 8:19 that Jesus had brothers...though he doesn't mention the sisters.
He doesn't segregate or note these brothers as being from another marriage of Joseph's.
Further, we have the account in Matthew where the people in His hometown noted:
Coming to His hometown, He taught the people in their synagogue, and they were astonished. “Where did this man get such wisdom and miraculous powers?” they asked. 55“Is this not the carpenter’s son? Isn’t His mother’s name Mary, and aren’t His brothers James, Joseph, Simon, and Judas? 56Aren’t all His sisters with us as well? Where then did this man get all these things?”… Mattnew 13:54-56 NASB
The locals identified Him as belonging to BOTH Joseph and Mary and the brothers were His.
There is no reference to them being from anyone other than Joseph and Mary.
It is true there are no passages saying Joseph went in and lay with Mary as seen in various places in the OT. However, there are no passages ever saying they went to the bathroom either...but I think we know they did.
Further, we have no passages describing Joseph actually working...yet we know he was a carpenter. Therefore we can say with confidence he did work at some point.
The New Testament is clear....Joseph and Mary had other children as long as one reads the passages in context and doesn't read their theology back into the texts.