One can honestly recount one's own experience from one's own perspective and still be incorrect about many of the details of that experience, be totally incorrect in one's interpretation of the causes of the events, and in fact suffer from a delusion or a form of mental illness. It doesn't make one a bad person, an unintelligent person, or a liar.
Shelby is an intelligent woman, an honest woman, a kind, sweet woman.
These things don't make the Holy Spirit real. They don't make her interpretation of her life's events 100% factual. It isn't judgmental to point that out. It could be done more nicely, perhaps, than has been done in this thread; or doubts about her veracity and sanity could simply be kept to oneself. But jumping on people who express doubts about the voices Shelby hears without any acknowledgement of the above facts seems unfair.