Mary wasn’t stained at all from original sin and then cleansed. God prevented that at the Immaculate Conception. People are born with original sin but then are cleansed through Baptism but they still have that fallen nature. Think of Original Sin as a mud puddle. You fall into it but you are taken out and wiped clean at Baptism. But you still did fall into the mud puddle and thus still have the fallen nature but you are wiped clean at Baptism. The Fallen nature is the effects of the original sin and causes you to commit personal sin. God prevented Mary from falling into the puddle, thus she doesn’t have the fallen nature and didn’t commit sin. She was full of grace.
May the peace of Christ be with you
Jason