In my opinion this kind of religious "extremism" is as bad as any drug addiction. I personally know people who use religion as a means of escaping the realities of life and I know first hand what it can do to families and relationships.
To tell the truth I do not really have trouble relinquishing credit for my accomplishments to a Higher Power. If your mom wants to regard St. Jo as such then I would'nt take that away from her. What I would have trouble dealing with is when other important matters are abandoned for the sake of religion or when you try to force feed me with your own religious beliefs.
Take care of yourself. Don't allow her to use religion to abuse control or shame you.