Yes, she did. She was preserved from original sin in anticipation of the salvific act of Christ on the cross. Without the cross, she could not have attained heaven either, because she would have had no benefit, anticipatory or otherwise, from Calvary.
She was, literally, a livng Ark of the Covenant for nine months. She carried the Word made Flesh in her womb. The Old Testament ark, so richly embellished as described in Exodus 25, was made as it was because it bore the Word of God in the form of the Ten Commandments. But this also was a prefigurement of Mary's future role. Many people read Revelation 12:1-6 and suppose that Mary is being referred to, and they are correct in doing so. But notice what is described *immediately* before these verses: "the ark of his covenant" (Rev. 11:19). Remember that, in the original text, there were *no* divisions into chapters and verses. An artificial separation appears dividing the end of chapter 11 from the beginning of chapter 12. In the original, they are part of a whole, perfectly self-contained in context.
Mary is NOT God. It's amazing that, no matter how many times we Catholics deny the charge, here on FR or elsewhere, we are continually accused of worshiping Mary and calling her divine. She is a *creature*, just like the angels, the saints, us, the animals, the plants and plain ol' dirt. But, would you say that an angel is more exalted in creation than a lump of mud? Are YOU more valuable than a worm? You already know the answers to these questions. But contained in the questions is a valuable point: there is a hierarchy to God's material creation just as there is in His spiritual creation (the angels). Mary is exalted above the rest of us, because she was the sinless God-bearer literally fulfilling the role of the Ark, only she did not merely carry a representative of God's word, she carried GOD Himself.
You deny, of course, that she was sinless. Nothing in the Bible *explicitly* says she was, so she couldn't be, etc. This underscores one of the problems with Sola Scriptura. You completely ignore the witness of the Church through history in matters not specifically addressed in Scripture. The only bridge between the time of Christ and our own, in terms of visible church structure, consists in the existence of the Catholic/Orthodox Churches. BOTH of them have continuous, uninterrupted and profound histories of veneration of Mary and the other saints. NEITHER of them has ever worshiped Mary or the saints as part of the Godhead. But isn't their combined witness in this matter telling? Protestantism is a Johnny-come-lately to this issue, and has jettisoned consideration of it, as it has jettisoned consideration of any teaching not specifically found in the Bible. But it misses so much in doing so! How arrogant for it to assume that the two elder witnesses to the constant teaching of the Church have no idea what proper Christian teaching is!
You balk at these things, not because they are wrong, but because they simply are not part of your *own* tradition. But, in rejecting the teaching authority of the Church, which predates the first word written in the New Testament, you reject, in reality, any credible and authoritative link to Christ's will for His future followers. Has it ever occured to you to ponder the witness of the only two groups who can claim apostolicity that have survived to the present? What if they ARE right about this and other issues?
Your situation is similar to being a Canadian and deciding that this or that phrasing of the US Constitution is "wrong" and needs fixing. But you do not have proper standing, even if you find things that are less than ideal in the wording!
You had better be *sure* that you're right in such matters as the one discussed here on this thread. For you to be right, there has to be a (minimum)1400 year gap, from the time of the last Apostle, where error was taught to the Christian believers. That puts little faith in Divine Providence, or the plain words of Matthew 28:18-20. If that 1400 year gap does *not* exist, you are on the wrong side of the issues. Without benefit of the Sacraments taught and dispensed throughout the 2000 year history of the Church, you will only have the uncertain supposition that God will honor your honest intentions with mercy to fall back on.
You're wasting your time. He is an autocephalic