The salutation of the Angel Gabriel is different from the usual
angelic greeting. It indicates that Mary was exceptionally "highly
favored with grace" (Greek: charitoo, used twice in the New
Testament; in
(1) Luke 1:28 for Mary - before Christ's redemption; and
(2) Ephesians 1:6 for Christ's grace to us – after Christ's
redemption).
Luke 1:28
And coming to her (Mary), he (the angel Gabriel) said,
"Hail, favored one (kecharitomene)"
Ephesians 1:4-6
(God) chose us in him (Jesus), before the foundation
of the world, to be holy and without blemish before him.
In love he destined us for adoption to himself through
Jesus Christ, in accord with the favor of his will, for the
praise of the glory of his grace (echaritosen) that he
granted us in the beloved.