So, you think the devil can tell people to return to God and to pray, believe in Jesus, and repent of sin? If you had really studied apparitions of the Blessed Virgin and what she says, you would know that is her message. There is no way the devil can say those things, so your assertion that Marian devotion is demonic is really stupid.
Yep. As long as the "Jesus" she proclaims is a strange kind of neutered cosmic momma's boy, rather than the majestic and reigning "Lamb slain from the foundation of the world." United Pentecostals have a Jesus they advocate, along along with exhortations to pray and repent. Muslims speak well of Jesus and are passionate about prayer and repentance. JWs have kind things to say about Jesus, and are big on prayer and repentance.
Finally, the closest parallel to the cult of the BVM, Mormonism, honors its Jesus and preaches prayer and repentance. Mormons have spiritual experiences, a "burning in the bosom," and testify to answered prayers. They have real encounters with a real self-aware spiritual entity -- a deity that is other than the God of the Bible.
Facts matter. Satan gladly appears as a god, or goddess, in order to bind souls to himself. Lovers of God and His truth do not settle for second-rate substitutes, imitations, and alternative spiritual universes.