Jesus was born without sin because He is God. Catholics believe that Mary was conceived without sin because God’s grace saved her from sin at the moment of her conception. Mary was not born without sin because of her own actions but only because of the Grace of God.
No one is born in sin because of their own actions, but because of the actions of Adam and Eve. And I can find no Scriptural basis to support the idea that Mary was born without sin. To say that Mary was born without sin and was without sin throughout her life would be to undermine the whole point of the Cross - that humans cannot be sinless, and it took the sacrifice of a perfect Lamb (Christ) to wash away our sins. If God would take away Mary's original sin, why wouldn't He do it for all - after all, God is not a respecter of persons.
Sorry, you certainly have the right to believe as you wish, but I can't buy it. When I see people praying to Mary and to "saints", that crosses over into idolatry for me, and I can't go there.