[CynicalBear]

The Holy Spirit through scripture only uses “full of grace” for Jesus and Stephen.

[annalex]

Both Jesus and Mary are said to have a fullness of grace and the expressions used are different. St. Stephen case is a Latin Vulgate mistransaltion.

Mary: κεχαριτωμενη, normatively translated "full of grace" or to obfuscate the meaning, "greatly favored" or something like that (Luke 1:28)

Jesus Christ: πληρης χαριτος, "full of grace"

St. Stephen: πληρης πιστεως και δυναμεως, "full of faith and power", Douay is in error here.