How is questioning her vocation any evidence of the Lord attempting to reach her? I suspect many people question their vocation, no matter what their occupation. There is no reason to assume that the Lord was behind her questions. For all you know, she may have gotten a letter from an old boyfriend.
Well each to his own opinion on the matter. I for one believe they are a prison and that which occurs there isn’t pretty. Enough nuns have escaped these prisons to tell their stories. I believe them.