I have an Evangelical friend who said "When I go to a doctor I don't want to talk to his mother." That is an interesting analogy. However, this Evangelical talks regularly with his pastor and asks the pastor to pray for him. The pastor doesn't turn him away by saying, "Don't talk to me! Don't ask me to pray for you! Go straight to Jesus!" The pastor has compassion and "intercedes" (stands in the gap) for him. He prays for the congregation and for individuals. He has compassion and wants to assist people in their relationship with Christ. This in no way diminishes Jesus' role as the Lord and Saviour.
Catholics ask Mary to pray to Jesus for us. She is interceding, kind of in the way a pastor might pray for you or me. Even in the Rosary we ask Mary to "Pray for us sinners." And we think she s quite good at that.
Mary is a "born again" Christian who received the Holy Spirit at the Pentecost and spoke in tongues 2000 years before Pentecostals got the gift.(Acts 1:14, 2:3) She knows how to pray - yes even in tongues!
In the movie "The Passion of the Christ," I was floored when I saw Mary at the foot of the Cross. I would like to have that woman pray for me. I ask her to do just that, pray for me. I also ask her to pray for you. I feel her prayers and I thank her for spending so much time praying for our world...
Other related readings about catholic spirituality