Mary is the mother of Jesus who appointed her as our mother also and our mediatrix between us and him. Catholics do not pray to Mary but for her to intercede with Him on our behalf just like people ask others to pray for them. Mary is honored by Islam and Christians and is a Jewish girl.
Some of her apparitions
Mystical City of God (The life of Mary as told to Mary of Agreda)
Mary did you know the song by the writer
Dedication to Mary: Pray for Vocations