In Catholic Theology, was Mary "Unable" to Sin?

Jesuit theologian [Fr. Kenneth Baker](https://en.wikipedia.org/wiki/Kenneth_Baker_(Jesuit)) states that Mary was not only free from sin but was "unable" to sin: > Two special factors rendered Mary impeccable or unable to sin. The > first was her constant awareness of God, living always in His > presence, and the second was her reception of special and > extraordinary graces. These special graces made it possible for Mary > to maintain a perfect harmony in her mind, will and emotions and to > recognize always what was the right thing to do and then to do it. > (Baker, Kenneth (2016). Fundamentals of Catholicism, Vol. 2. Ignatius > Press. ISBN 978-1-68149-732-7.) The Catholic Encyclopedia on "The Blessed Virgin Mary" seems to confirm this when it says that her sinlessness was due to "divine privilege" and that she never experienced temptation: > Theologians assert that Mary was > impeccable, not by the essential perfection of her nature, but by a > special Divine privilege. Moreover, the Fathers, at least since the > fifth century, almost unanimously maintain that the Blessed Virgin > never experienced the motions of concupiscence. Does the Catholic Church teach simply that Mary did not sin, or that she was unable to sin?