I am not trying to refute the original poster, nor do I have anything against Catholicism, having been raised one myself, served as an altar boy, gone to Catholic schools and personal close friends with priests including a best friend who became a priest.
Nor do I think challenging this person's credentials as a nun has any bearing on what it is they have to say, because anyone could say them and still be correct. It would be as though you were told a house was on fire by a man claiming to have been a former fireman, and people doubted the house was actually on fire because his tenure as a fireman was dubious.
My observations as a Catholic were that, if you observed objectively, veneration of Mary pretty much was the same as outright worship. When I talked with priests about it, their reaction was more or less "how much can it hurt?". Even as a believer it sometimes bothered me that we worship God in a human skin called Jesus, even more it bothered me that a person who
isn't divine in any sense of the word would warrant such attention.
So as a young Catholic, I eschewed anything resembling worship of a person, whether it was the mother of Jesus or any "saint". I avoided rosaries, devotional scapulars or medallions. I wasn't going to let my Muslim or Sikh school mates ridicule my religion as polytheistic.