Don't be confused by your friend, who frankly is wrong in every respect. She is a fundamentalist and has gravely wrong conceptions about:
- the Bible
- Revelation, and
- magisterial authority.
In short, she is ignorant. I mean that in a charitable way. If she knew the truth she would not be spewing such falsities.
Your friend claims to use the Scriptures alone as the source of truth and revelation, yet she rejects the authority by which we have the canon of Scripture. She uses her arguments speciously, such as claiming that Moses and Elijah only spoke to Jesus because he was God.
- Where does it say that in the Bible? <It doesn't.>
The fact is, Jesus is the Man-God. Yes, fully human in every respect, and what he did on earth was proper to a man. He was a model for us to emulate in every respect. There is not one thing that Jesus did that was not possible for us. Ponder that for a moment.
- Miracles? He told his disciples they would do even greater ones.
- Resurrection? — also for us.
- Suffering and persecution? — also for us.
Yes, Jesus is God, but he was/is a friend to the disciples, a brother to His family, of which we all are part. A Son to a wonderful Mother that He shared with us. He is family. She needs to rethink her whole view of Scripture and the family of God.
Christ gave us His Church. Founded it on an Apostle named especially by Him — Peter. Just like God gave the special persons connected with His Covenants a new name: (Abram-Abraham, Jacob-Israel, Simon-Peter). This new naming gave Peter (and his office) a vital role in the New Covenant. She rejects the Pope, so she rejects Jesus' appointee. There are many other errors she is lost in, because Protestantism has lost the truth about the:
- the Saints, and
- other 'fundamentals' of the faith.
Marian apparitions have happened in history because God wants them to happen. He wants Mary to have an integral role in salvation history, just as He wants you and I to play a part in His plan.
Your friend will tell you that nothing can be added to the saving work of Christ, and that is true if you look at the intrinsic worth of what Christ accomplished; but the truth is, God deigns to make what His other family members do relevant and important — because it brings Him greater glory!! Think about that.
- If you had several children, wouldn't you want them each to be succeed?
Even if they were handicapped and limited?
God has only one begotten Son, but we are His children by adoption and He therefore wants us to be part of His Plan. We bring Light and Salt to the world. We are channels of grace. We pray for each other. We love, not because we are equal to God, but because God made it possible for us to do so in His Grace, and actually desires us to do so. That said, Mary is the perfect example of this. No one is closer to Jesus (except the Father and Holy Spirit) besides Mary. No one has greater love for all of God's children than the Mother who was entrusted to that family. Mary is our Mother.
Your friend is missing God's greatest gift. She is lost in arguments over what can and cannot be possible in terms of apparitions, and missing the bigger picture. Nothing Mary has ever said in any apparition contradicts the faith because she is with God and knows the truth.
If there are errors, it is when humans have put their own take on things. Your friend dismisses the possibility of apparitions and therefore all the content of what she said.
Her premise is that no more prophetic revelation can take place after the close of the Apostolic Age and the Catholic Church has a similar view. What happens in apparitions are not considered binding revelation but when approved are open to acceptance by the faithful, for they are found not to contradict the faith.
In other words, you are free to believe in them if you want, but you are not bound to believe in them. The Church reviews the content, the integrity, the character, circumstances, and other relevant data and information to discern if the apparitions are really something cloaked in evil.
If the evidence supports authenticity of an apparition(s), the Church may give her approval so the faithful know that they have researched them well enough to find them not a danger to the faith but let's be clear, apparitions are possible, despite what you friend believes based on her misreading of the Bible.
You should study the differences between Catholicism and Fundamentalism.
A good book written almost 30 years ago called Catholicism and Fundamentalism by Karl Keating would be a good start. You will see the distortions and misconceptions of fundamentalists laid out in detail, with hundreds of Scripture quotations to back up our faith. We need to know our faith before we can share it effectively, and not be thrown into confusion and error.
Do some homework and you will be confident, happy, and able to share the faith in charity and truth.