Andy Byler writes on the Biblical basis for the dogma of the
Immaculate Conception:

 +  I will put enmity between you [the Serpent] and the woman, and
 + between your seed and her seed, she [can also be read he] shall
 + crush your head and you shall bruise her [or his] heel.
 + -Genesis 3.15

 +  He who commits sin is of the devil ...    -1 John 3.8

 +  Hail, full of grace [greek - kecharitomene], the Lord is with
 + thee ...    -Luke 1.28

In the Hebrew of Genesis 3:15, the gender is clearly masculine.

 + HE shall crush your head, and you shall bruise HIS heel.

The Latin has feminine forms, only by an accident of grammar.

Andrew stated that KECHARITOMENE means not just "full of grace" but
"having a plenitude or perfection of grace." The word is used
elsewhere in the New Testament only in Ephesians 1:6

 + Unto the praise of the glory of his grace, in which he hath
 + GRACED us in his beloved Son. (Rheims-Douay translation)

I cannot find any indication in my dictionary that the verb implies
anything as strong as Andrew suggests, nor does the Ephesians
passage suggest that the verb means "to preserve from any taint of
original or actual sin from the first moment of existence." I should
like to see a comment on the meaning of the verb, preferably not
from s writer who is discussing Luke 1:28 at the moment.