That is not the issue, but the attribution to her of such great powers, incldg. being the dispenser of all grace, etc., etc. Jesus Himself was given power in Heaven and earth, but no where do we see it even intimated that departed saints are to be heavenly objects of prayer (unless you suppose Abraham was in Heaven in Lk. 16:19ff, but even then the “prayer” was not as thoughts from one’s heart), or are given power that even God is subject to. That is word of faith theology, not Biblical doctrine.
I would not advise you to defend St Bernard here.
You guys go ahead and practice your very edited sort of Sola Scriptura. We find Jesus promising to the Apostles that he will lead them into all truth, and we trust Him so much that we trust him even when the successors to the Apostles and the priests they ordain act like bozos.
By contrast, your side holds the Scripture up against the Church, ignoring how NoGrayZone's posts and the debate between Arminians and Calvinists demonstrate the inability of Sola Scriptura to serve as an authority.