BTW Our Lord said that the Good Thief crucified at His right hand, would be with Him in Paradise. But the Good Thief wasn't baptized in water at all. So the Church, reflecting on the Scriptures, also teaches "baptism of desire," namely that a person who even implicitly desires baptism can receive sanctifying grace.
Catechism of the Catholic Church: "Those who die for the faith, those who are catechumens, and all those who, without knowing of the Church but acting under the inspiration of grace, seek God sincerely and strive to fulfill his will, are saved even if they have not been baptized" (CCC 1281)
I am very surprised that a Catholic would use the same old, worn out argument that many "faith only" advocates use to explain the thief on the cross.