Heresy of the Perpetual virginity of Mary

Heresy of the Perpetual virginity of Mary:
Matthew 1:25  And knew her not till she had brought forth her firstborn son: and he called his name JESUS. (Why called Firstborn son is she has only the Lord Jesus? And why use the word “till”?) I slept from 9.00pm till 5.00 am. I’m I still sleeping after 5.00am?
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? 
Matthew 13:56  And his sisters, are they not all with us? Whence then hath this man all these things? 
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.
Mark 15:40  There were also women looking on afar off: among whom was Mary Magdalene, and Mary the mother of James the less and of Joses, and Salome;
Gal 1:19  But other of the apostles saw I none, save James the Lord's brother.
Till meaning: preposition - up to (the point in time or the event mentioned):

See also Mark 3:31-34; Luke 8:19-21; John 2:12; and Acts 1:14.

Catholics claim, correctly, that the Greek terms for "brothers" and "sisters" in these verses could also refer to male and female relatives, not necessarily literal brothers and sisters. However, the intended meaning is clear, they thought Jesus to be Joseph’s son, the son of Mary, and the brother of James, Joseph, Simon, and Judas, and the brother of the unnamed and unnumbered sisters. Father, mother, brother, sister. It is straining the meaning of the text to interpret “brothers” and “sisters” as "cousins" or "relatives" with the mentioning of Jesus’ mother and father.