My college friend started to study the Bible and started really well. In fact, she quit her job (she's a CPA) when she realized it was causing her to sin without us challenging her. But she suddenly sent me a message saying she will no longer attend the service and will not continue to study the Bible. After some probing, she confessed she didn't want to leave the Catholic Church because of "Mother Mary"; saying she is part of our salvation. She even provided this scripture in John 19:26-27 (She added had it not been for us challenging her to read the book of John she would have not known about this). So I asked her where in the scripture does it talk about Mary having to do with our salvation? She answered: Since Mary is Jesus' mother, the actual blood shed was of Mary's. We can't expect to find all the answers in the scriptures, as one of the disciple said, everything God has done cannot be contained in one single book. (paraphrase). How do I help her?
My guess is that, despite what your friend said, this idea that the blood of Jesus was Mary's came from talking to a Catholic friend, not from reading the Bible. In any case, she has every right to talk to her Catholic friends about what she is studying. My advice will depend on whether your friend is willing to continue talking and studying the Bible. If she is not, then there will not be a lot you can do for her. If she is willing to talk and study the scriptures, then I suggest that you begin by going straight to John 19:26-27. In this passage, Jesus, who was the head of his household and therefore responsible for his mother, is asking John to take care of his mother. There is no conceivable way to see that this passage could possibly be teaching that Mary has any role in our salvation. In fact, there is not a single scripture in the Bible which even hints at the possibility that our salvation might depend on Mary. Mary is not even mentioned in Acts or in any of the letters of Paul or in Hebrews. In the many gospel sermons in Acts, Mary is literally not even mentioned. If you read the writings of the early church, Mary was never held to be of any importance in our salvation. Mary was a wonderful woman. I believe she is one of the most faithful people in the entire Bible, but there is not even the slightest suggestion anywhere in scripture that we should hold her up above other disciples of Jesus or worship her or revere her or give her a special place other than as a faithful Christian. The blood that Jesus shed on the cross was Jesus' blood. Where one would get the idea that it was Mary's blood I have no idea but it certainly is not supported by any scripture. If this were true, then I suggest that it would be stated or at least implied in the scripture. The fact that not everything God has done can be contained in a single book is true, of course, but on the other hand the Scripture contains everything we need for salvation and for every good work (2 Timothy 3:16). The fact that the Bible does not answer every question does not mean that we are free to propose a major doctrine, such as that we are saved by the blood of Mary, without any scriptural support. We can assume that all essential teachings are in the Bible! There is not even a single hint in the Bible that we should hold up Mary above other people. Only Jesus is to be worshiped and given special honor. I hope your friend will be able to see that what she has been thinking is not supported by the Bible.