This topic has been given serious thought in the Christians-Only section of this website, as well as other websites that I've participated in over the years.
One of the questions that has been asked is how Jesus could have married and then had a family in the 18 years between when he was 12 and when he started out in his ministry citca 30 AD. The argument for his having gotten married developed from the accelerated rate at which children of that era achieved adulthood. With the average lifespan of a male in Judea being only 35 to 40 years, families had to be started when the parents were only teenagers themselves in order to provide the necessary support.
Then we took a second look at the Julian calendar. In 525 AD it was changed so that instead of recording time from the start of an emperor's reign, it would record time from the birth of Christ. But the people who decided that got the math wrong, due to their not 'butting' the reigns of the emperors up against each other correctly.
When other scholars who had more accurate information checked the figures used, they found that the year 525 AD should have been 535 AD, at the very least. Instead of the death of Herod the Great as having occurred circa 3 or 4 AD, the math now showed that it had occurred circa 6 BC. (His son Herod Archelaus ascended the throne in 4 BC, and since he would have needed to go to Rome first to get the blessing of Augustus Caesar, this would mean that Herod the Great had died about 2 years earlier).
For those of us who accept Scripture, this pushes the time of Jesus' birth back by at least 10 years. We know that Joseph had already taken them to the safety of Egypt prior to Herod's death, so this alone would make Jesus' age in 6 BC as at least 3 years old. We do not know how long The Holy Family was in Egypt, so Jesus could very well have been older.
But we do know that his ministry started in the 15th year of Tiberius' rule. This is stated in Luke, who guessed that Jesus was somewhere around 30 years of age when his ministry started. We also suspect that his ministry lasted 6 years, rather than 3. Scholars record the 15th year of Tiberius' reign at coinciding with 27 AD in the presentday Julian calendar. They also see it as more accurate that he was a rabbi (a teacher) for about 3 years prior to his calling the apostles to him (the thought of someone just appearing suddenly 'out of the blue' and telling 12 men to drop everything and follow him didn't really make sense. Those men knew Jesus, with the possible exception of Nathaniel).
So he and his apostles began his mission as its recorded in Scripture in 30 AD. This calculates to Jesus' being at least 39 years old when that mission began, with some (including myself) believing that he was 42 years old. So what had occurred in the intervening 30 years between when we last saw Jesus as a child and when we start seeing him as a minister with disciples?
He had obeyed all the laws and commandments of Torah, and one of those laws is this one:
God blessed them and said to them, "Be fruitful and increase in number; fill the earth and subdue it. Rule over the fish of the sea and the birds of the air and over every living creature that moves on the ground."
This law is repeated in Genesis 9:1, following the Great Flood.
We know that Jesus was married sometime during the 'lost years' of his life. He is called 'rabbi' in Scripture, which title required that the man have a family himself (there was none of this nonsense of having a teacher that was sworn to celibacy advising married couples as to how to make their marrieage stronger). The only exceptions were those who chose a monastic life, and Jesus was not one of those people.
He is called rabboni by Mary Magdalene in John 20:16. According to those who know hebrew and aramaic, as well as the societal etiquette of 1st century Judea, the word 'rabboni' had three different meanings, depending on who was saying it. If a slave called a man 'rabboni' it meant master; if a freeman called another man 'rabboni' it meant teacher; but if a woman called a man 'rabboni' it always meant 'husband'.
In those Scriptures where the women are named, Mary Magdelene is always named first if she is there. This was formal sentence structure of that time. If a man was with a group of women, his mother was always to be listed first if he was single and she was present, but his wife was always to be listed first if he was married and she was present.
Also, his biographers were all observant Jews who were learned in the laws of Torah. They might have called Jesus a good man if he had remained single, never having a family, but they would never have stated that he obeyed God's laws perfectly. The law to have a family would have been realized by them as not having been fulfilled.
So what do we have?
1. Jesus is born somewhere during the timeline between 9 and 12 BC.
2. This means that Jesus' journey to the temple in his twelfth year occurred sometime between 1 and 3 AD (there is no such year as 0 AD). Afterwards he returned home with Joseph and Mary, and all we know about him from that point until he appeared at the River Jordan is that he was obedient to Mary and Joseph. But this provides us with another clue. A Jewish father had three responsibilities to his sons; he was to see to it that they studied Torah, he was to teach them a trade so that they could provide for their families, and he was to find for them wives.
3. He helped in the rearing of his younger siblings, was conscientious in supplying his parents' physical needs, in all probability took over as 'the man of the house' when Joseph died, married in accordance with the laws of Torah, and had children of his own.
4. Circa 27 AD he went out to start his ministry, having reared his children to adulthood. Three years later he called the apostles to him, having preached to them and taught them over the previous three years.
5. During this time he was still conscientious concerning caring for his mother. Being the eldest, it was his responsibility to keep food on her table and a roof over her head. Rather than abandoning her to whatever kindnesses his younger siblings might find it in their hearts to show her, He had seen to it that one or more of his own children would continue 'running the business' and providing for her needs. To do otherwise would have been to violate the fifth commandment (Honor your father and mother), and would have been recognized as such by his disciples.
So there are those of us who believe that Jesus did indeed marry and have children during those years betwen when he was 12 and the year 30 AD. This would have fulfilled the laws of Torah.