Is anyone impeccable?

I saw something by Jimmy Akin today in which he said many people confuse the ideas of infallibility and impeccability and believe that Catholics are claiming the pope is the latter while in reality we claim the pope, under very specific circumstances, is protected by the former.

Just to be clear: Infallibility is a special charism of the pope which means that he speaks without error in matters of faith and morals when he speaks ex cathedra in his role as Bishop of Rome.

On the other hand, impeccability is the absence of sin. It may also be defined as being incapable of sinning. Is there anyone who is impeccable?

Philosophically speaking, God must be impeccable, as it is logically impossible for him to act against his own nature and will. Jesus is God and therefore is also impeccable.

The Church has also defined that all those in Heaven who experience the beatific vision are impeccable. They are no longer capable of sinning. St. Thomas Aquinas goes further to teach that even the souls in purgatory are impeccable as well.

As Catholics, we believe that Mary was conceived without sin during the Immaculate Conception, which we just celebrated on December 8. This means she was preserved from original and personal sin at the moment of her conception and remained sinless her entire life. Her special gift of sinlessness was achieved by Christ's sacrifice at Calvary pre-emptively.

Does the fact that Mary was preserved from all sin also mean she was impeccable? 

Kenneth Baker, a Jesuit priest, former president of Seattle University, and editor-in-chief of Homiletic and Pastoral Review writes the following:

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.

I am not sure if this is the doctrine of the Church or his opinion as a theologian. Regardless, never sinning and being unable to sin are somewhat similar.