Mary the mother
The Templar Church sees Mary-the Mother, only as Jesvs birth mother, not as "mother of GOD", since Jesvs is not God, but the only begotten SON of GOD. And how could a human ever be the mother of a god? So, Mary is neither the mother of GOD or a Goddess!
Mary sure was privileged to be the mother of the messiah, and sinfull birth mother to Jesvs, the Son of GOD, but this does not make her mother of God, because GOD does not have a mother, for GOD was never born but always existed, with no beginning and no end.
GODd-the father of our Lord Jesvs, can be compared (in this situation) to the gods of old greeks stories, who came down and had relations with the earthly women. The Demi-gods are the offspring of these gods. Eventhough GOD almighty never really can down from heaven, he made Mary pregnant through the transver of the life of his only begotten son to the womb of this woman, using his holy spirit. Really a wonderfull miracle!
So after Jesvs was born, Mary was no longer, a virgin. Her womb was opened by the birth of Jesvs, the Christ, and she continued to bare more children for her husband Joseph. (see: Jesvs brothers.) This does not mean she is not an important devoted woman. On the contrary! She was the giver of birth to the Messiah, the first to recognize his special role and a life long diciple of the Lord. And as this, a wonderfull example for all women to follow!
(Luke 1:42 and loudly cried out: “Blessed are you among women, and blessed is the fruitage of your womb!)
But like all sinfull mankind, she grew old and died.
The simple answer is YES! After Joseph married Mary (the birth mother of Jesvs) he had merital relations with her. So yes, Jesvs did have younger siblings.
(Matthew 12:47 So someone said to him: “Look! Your mother and your brothers and sisters are standing outside, seeking to speak to you.”)
Although we do not know exactly who many brothers and sister Jesvs had, we know that Jesvs was not the only child of Joseph and Mary.
Early in Jesvs live, his younger siblings did not believe he was the messiah, slowly but surely, after seeing him perform so many miracles and for sure after his death and resurrection many of them did put faith in him after all.