Sorry, mis-read it. I would imagine that if we where all born “Full of Grace” that we would then lack free will.
Secondly if Adam and Eve did not receive the punishment due for their transgression, (and us as decendants of our first parents) that would be a miscarriage of justice. God is merciful, but mercy does not rule out justice. God does freely offer graces that we are free to accept or reject, however He does not force His graces on us. To deny this would be to accept the false premise of Absolute Predestination which John Calvin based his heresy on.