All good Jewish wives believed it was their duty to be the "helpmeet" of their husband. Having "children" was a blessing, part of the fulfillment of a "quiver full". Think of how many stories in the bible are about women who are having difficulty having children and how important it was to them. Mary had four other sons, Joseph, James, Jude, and Simon. Some think that they really belonged to Joseph and not Mary. Here are some passages where the other sons of Mary by Joseph are mentioned (Matt. 12:46; 13:55; Mark 6:3; John 2:12; 7:3, 5, 10; Acts 1:14; 1 Cor. 9:5; Gal. 1:19).
Mary was never called to be a virgin forever. She got married. Joseph chose to abstain from " knowing" his wife until after Yeshua was born.
Matt 1:20 But as he considered these things, behold, an angel of the Lord appeared to him in a dream, saying, “Joseph, son of David, do not fear to take Mary as your wife, for that which is conceived in her is from the Holy Spirit. 21 She will bear a son, and you shall call his name Jesus, for he will save his people from their sins.” 22 All this took place to fulfill what the Lord had spoken by the prophet: 23 “Behold, the virgin shall conceive and bear a son, and they shall call his name Immanuel” (which means, God with us). 24 When Joseph woke from sleep, he did as the angel of the Lord commanded him: he took his wife, 25 but knew her not until she had given birth to a son. And he called his name Jesus.
This term "know" or "knew" is often used in the biblical sense of sexual intimacy. "Now Adam knew his wife Eve and she conceived." I believe it from the clear words of Yeshua on marriage being the place for two people to become "one flesh" only found through intimacy.