Mary was only a virgin until the birth of Jesus.
After his birth she had normal sexual relations with Joseph and had four more boys and at least two girls.
Matthew 1:18 Now the birth of Jesus Christ was on this wise: When as his mother Mary was espoused to Joseph, before they came together, she was found with child of the Holy Ghost. 19 Then Joseph her husband, being a just man, and not willing to make her a publick example, was minded to put her away privily. 20 But while he thought on these things, behold, the angel of the Lord appeared unto him in a dream, saying, Joseph, thou son of David, fear not to take unto thee Mary thy wife: for that which is conceived in her is of the Holy Ghost. 21 And she shall bring forth a son, and thou shalt call his name JESUS: for he shall save his people from their sins. 22 Now all this was done, that it might be fulfilled which was spoken of the Lord by the prophet, saying, 23 Behold, a virgin shall be with child, and shall bring forth a son, and they shall call his name Emmanuel, which being interpreted is, God with us.
Luke 1:26 And in the sixth month the angel Gabriel was sent from God unto a city of Galilee, named Nazareth, 27 To a virgin espoused to a man whose name was Joseph, of the house of David; and the virgin’s name was Mary. 28 And the angel came in unto her, and said, Hail, thou that art highly favoured, the Lord is with thee: blessed art thou among women. 29 And when she saw him, she was troubled at his saying, and cast in her mind what manner of salutation this should be. 30 And the angel said unto her, Fear not, Mary: for thou hast found favour with God. 31 And, behold, thou shalt conceive in thy womb, and bring forth a son, and shalt call his name JESUS. 32 He shall be great, and shall be called the Son of the Highest: and the Lord God shall give unto him the throne of his father David: 33 And he shall reign over the house of Jacob for ever; and of his kingdom there shall be no end. 34 Then said Mary unto the angel, How shall this be, seeing I know not a man? 35 And the angel answered and said unto her, The Holy Ghost shall come upon thee, and the power of the Highest shall overshadow thee: therefore also that holy thing which shall be born of thee shall be called the Son of God.
Matthew 13:55 Is not this the carpenter’s son? is not his mother called Mary? and his brethren, James, and Joses, and Simon, and Judas?
Mark 6:3 Is not this the carpenter, the son of Mary, the brother of James, and Joses, and of Juda, and Simon? and are not his sisters here with us? And they were offended at him.
Galatians 1:19 But other of the apostles saw I none, save James the Lord’s brother.
The Roman Catholic Church has invented the false doctrine of the perpetual virginity of Mary.
It is not found in the Bible.
I hope you find this helpful.