No, He would not make His Father a liar for her sake. The whole thing is fraught with error. For instance, if Mary was born without original sin, how can that be, when Adam's sin is passed down through the father... With Yeshua, this point is perfectly explained: His father was not of Adam. With Mary, we know her father was of Adam.
And the curse of original sin included aging and death, yet the same church tradition you all rely upon (infallibly, btw, according to your leaders) claims that she grew old and died - If she were without the original curse, she would not grow old, and she would not die. What nifty bit of magic explains that away?
Scripture says nothing at all about "Adam's sin" being passed down through the father. Catholics understand original sin principally as the absence of God's indwelling divine life anyway, and you don't pass down an absence -- you fail to pass down the presence to whose lack the absence corresponds.
As to your question about aging and death, freedom from those evils were lost by Adam's sin, and Mary was not given them back. In that sense, she was less blessed than Eve originally was! The loss of those freedoms (called "preternatural gifts" by theologians) isn't the essence original sin, however.