i hope if this answer your qurstion
Mary was accepted by God, and was brought up in a good manner after she was put under the care of Zachary. Through her devotion and righteous upbringing and the prayer from her mother, Mary became the best woman to ever live as depicted in the Quran in the verses 3:42:
OK, I’m beginning to understand. St. Mary was kept pure because of the circumstances surrounding her birth,
not because of the special role she would play as the future mother of Jesus.
I’m reminded of the occasion on which an angel told Zachariah ahead of time about his future son John the Baptist, as recorded in Luke chapter one:
[11] And there appeared to him an angel of the Lord standing on the right side of the altar of incense.
[12] And Zechari’ah was troubled when he saw him, and fear fell upon him.
[13] But the angel said to him, “Do not be afraid, Zechari’ah, for your prayer is heard, and your wife Elizabeth will bear you a son, and you shall call his name John.
[14] And you will have joy and gladness,
and many will rejoice at his birth;
[15] for he will be great before the Lord,
and he shall drink no wine nor strong drink,
and he will be filled with the Holy Spirit,
even from his mother’s womb.
[16] And he will turn many of the sons of Israel to the Lord their God,
[17] and he will go before him in the spirit and power of Eli’jah,
to turn the hearts of the fathers to the children,
and the disobedient to the wisdom of the just,
to make ready for the Lord a people prepared.”
Oddly enough, the New Testament nowhere discusses the conception or birth of St. Mary…