It must first be recalled that the Catholic Church does not teach that these visits of Mary are a matter of either faith or morals for Catholics. These fall in the class of private devotion. The Catholic Church also teaches that there is no new public revelation possible after the death of the Evangelist John. Any thing else approximating new messages would be private revelation only. The Catholic Church applies the teaching of the Bible to her judgment of such private devotions.
Every good tree bears good fruit, and a rotten tree bears bad fruit.
So by their fruits you will know them. Neither can salt water yield fresh. The tests of such apparitions of Mary have shown that nothing in her messages and consequent devotion contradicts the word of God and the constant teaching of the Church. The Church has made and continues to follow the Biblical tests of the spirits and approves some such apparitions as of the Spirit. It remains for all Christians of a renewed mind and of the Spirit of the Lord to follow the Biblical mandates of testing spirits and the fruit of the tree as the Catholic Church has done.