Gertrude the Great (1256–1302) was a German nun who is recognized as a saint by the Roman Catholic Church, but was never formally canonized. I don't know if it's related, but apparently her views on the veneration of Mary were outside the norm compared to her contemporaries:
Of special interest at a time when devotion to Mary was so strong is Gertrude's concern that veneration was being given to Mary that properly belonged to Jesus Christ, who, possessing maternal as well as masculine characteristics, left no need for a feminine expression of deity. (Everett Ferguson, Church History, I)
Ferguson goes on to say that Gertrude still highly regarded Mary, and was concerned that Mary found her devotion to Christ displeasing.
Much more could probably be said about Gertrude's mariology. But Ferguson's brief summary makes me wonder: does Catholicism today consider Gertrude's mariology in line with its teachings, or not? And if not, is there reason to believe that this divergence prevented her from being formally canonized?
Note that I'm not limiting my question specifically to whether anything contained in Ferguson's summary would be problematic. I'm asking about Gertrude's mariology more broadly.