Matthew 1:18-25 (ERV) reveals the record of Jesus’ conception and birth:
“This is how the birth of Jesus the Messiah happened. His mother Mary was engaged to marry Joseph. But before they married, he learned that she was expecting a baby. (She was pregnant by the power of the Holy Spirit.) Mary’s husband, Joseph, was a good man. He did not want to cause her public disgrace, so he planned to divorce her secretly. But after Joseph thought about this, an angel from the Lord came to him in a dream. The angel said, “Joseph, son of David, don’t be afraid to accept Mary to be your wife. The baby inside her is from the Holy Spirit. She will give birth to a son. You will name him Jesus. Give him that name because he will save his people from their sins.” All this happened to make clear the full meaning of what the Lord said through the prophet: “The virgin will be pregnant and will give birth to a son. They will name him Immanuel.” (Immanuel means “God with us.”) When Joseph woke up, he did what the Lord’s angel told him to do. He married Mary. But Joseph did not have sexual relations with her until her son was born. And he named him Jesus.”
As stated in verses above, Mary was a virgin when Jesus was born and Joseph and Mary had no sexual union until after Jesus’ birth. Was Jesus an only child or did Jesus have any half-siblings? Did Mary conceive any children with Joseph? The scriptures tell us Jesus did, indeed, have brothers and sisters!
In Matthew 13:55, 56 “Isn’t this the carpenter’s son? Isn’t his mother’s name Mary, and aren’t his brothers James, Joseph, Simon and Judas? Aren’t all his sisters with us?
So, Jesus had four half-brothers and at least two half-sisters. These children were the fruitage of Joseph’s and Mary’s marriage.