Consider this: Jesus is not just our Savior against sin, but also death. Mary, being mortal, would be subject to death, whether or not she were sinless.
Please listen to me my friend. The belief that Mary was sinless is a made up story by men.
There is absolutely ZERO/NONE/NADA Scriptures to support the idea.
Mary was a blessed woman and she gave birth to Jesus the Christ but she was a human woman and as such was a sinner just like every other human woman.
Do you not understand that by saying that Mary was "Sinless" you are by default making her equal to Jesus who was God in the flesh.
The ONLY SINLESS woman to have lived was EVE and that only lasted a few days until she ate that apple. Then she was a sinner as are all other women.
As a Catholics, you do not find this doctrine from the context of Scripture but from making a pretext out of the Scripture from their Church tradition (which happens to be written down). But again it is not apostolic tradition.
If Mary was conceived without sin then her parents would have certainly known and would have assumed she was to bare the Messiah. The Catholics say she became sinless later in life. This would mean God took someone who has the nature of sin and completely change them to be sinless like Jesus Christ--without a virgin birth.
Logic, and moral reasoning along with the proliferation of ALL the Scriptures one would certainly think that such a miracle would be mentioned in the Scripture, somewhere,
but it is not! The Bible has no hint of such a thing to occur and actually says the very opposite in no uncertain terms in Romans 3, Aacusing all of humanity to be under sin except for one, the God/man with the virgin birth.
Now, instead of debating this.....think for a moment. Open you Bible to Genesis
3:15-16. Do you see there where God pronounces a judgment on sinners and one of those is pain in child birth.
Now, ask a another Catholic, look it up for yourself and you will discover that one of Catholics teachings is that Mary is the woman of Rev. 12.
Now YOU think this through........
If Mary is the woman of Revelation 12 as Roman Catholics say, it describes her with birth pains which according to the Bible is a judgment on sinners.
Now maybe you and other Cathoics can explain that.