Have you read the catholic teachings on Mary? There's tons of them. They give her a lot of power not attributed to her in the Bible.
.Mediatrix
We constantly seek for help from Heaven - the sole means of effecting anything - that our labours and our care may obtain their wished for object. We deem that there could be no surer and more efficacious means to this end than by religion and piety to obtain the favour of the great Virgin Mary, the Mother of God, the guardian of our peace and the minister to us of heavenly grace, who is placed on the highest summit of power and glory in Heaven, in order that she may bestow the help of her patronage on men who through so many labours and dangers are striving to reach that eternal city. ..showing that the Catholic Church has always, and with justice, put all her hope and trust in the Mother of God. SUPREMI APOSTOLATUS OFFICIO ENCYCLICAL OF POPE LEO XIIION DEVOTION OF THE ROSARY
Based on this why do catholics need Christ?
Our Lady of Victory, Pray for Us.