[Desdemona]

Well, I don't know much about her, but as she obviously was pious and very smart and wrote extensively...why not? How extensively have her writings been studied?

[Pyro7480]

I would think rather extensively, since the spreading of the Divine Mercy devotion was banned for a time, due to a bad translation of the Diary from Polish into Italian when it first made its way into Vatican circles. But before Paul VI died in 1978, he lifted the ban. I assume when the cause for Faustina's canonization was taken up, they took a thorough look into the Diary. I don't think they found any doctrinal problems with it. I know some theologians have been critical of the Divine Mercy message, but I don't remember all of their criticisms.