In any peril you can obtain salvation from this glorious Virgin

The Angel says that the Blessed Virgin is full of grace with respect to three things. 

-First, with respect to the soul, which has every fullness of grace (...)

-Second, she was full of grace with respect to the overflow of soul to flesh or body. For it is great for the saints to have enough grace to sanctify their soul; but the soul of the Blessed Virgin was so full that from it grace flowed into her body, in order that with it she might conceive the son of God. 

Thus Hugh of St. Victor says: "Because the love of the Holy Spirit burned so ardently in her heart, she was able to do wonders in the flesh, so that from it might be born God and man."  Luke 1:35: "The Holy One which shall be born of thee shall be called the Son of God." 

-Third, with respect to [grace's] distribution to all men. For it is a great thing in any saint that he has so much grace that it suffices for the salvation of many, but when enough is had for the salvation of all the men in the world, this is the greatest, and so it is with Christ and with the Blessed Virgin.

For in any peril you can obtain salvation from this glorious Virgin. Hence the Canticle of Canticles 4:4: "a thousand bucklers" (that is, protection against dangers) "hang upon it." Again, in every work of virtue you will find her ready to help. Therefore, she herself says in Ecclesiasticus 24:25: "In me is all the grace of the way, in me is all hope of life, and of virtue".

Saint Thomas Aquinas, on the Hail Mary (On the Angelic Salutation)