That particular method of scriptural interpretation is called eisegesis.
IOW, you declare a doctrine and then after you have declared your doctrine, you go and look for scripture verses that can be stretched and twisted to fit your particular doctrine.
There is no scriptural basis for the contention that Mary was born without original sin. There are plenty of verses to the contrary.
Amen.
"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 6:3 "I am become a stranger unto my brethren, and an alien unto my mother's children. For the zeal of thine house hath eaten me up; and the reproaches of them that reproached thee are fallen upon me." -- Psalms 69:8-9 "For neither did his brethren believe in him." -- John 7:5 "But ther of the apostles saw I none, save James the Lord's brother." -- Galatians 1:19"Then Joseph being raised from sleep did as the angel of the Lord had bidden him, and took unto him his wife: And knew her not till she had brought forth her firstborn son: and he called his name Jesus." -- Matthew 1:24-25