Here’s the way I was taught to understand Mary’s sinless status: God her Savior preserved her sinless. She did not do this on her own, it was done for her from her immaculate conception, so that she could be a pure mother for His only begotten Son, Who is our Savior. He lifts us out of the pit, but God prevented her from falling in, in the first place.
She is indeed special, among all created by God. She is not a goddess, she is human kept from all stain of sin by God, her Savior. She acknowledges this in the magnificat you quoted from Luke.
I am curious as to why you cling tighter to the unsubstantiated stuff that you were taught years ago, then to reading the Bible today and clinging to the KNOWN Word of God?