This nurse, as were some other American nurses, were recruited to Tibet to teach nursing. She was very up and above board and not a liar. She was a Christian and she was held to very strict rules and regulations. She even had to dress in their style clothing (which she had brought to the luncheon to show us)! She had photos of the homes with the objects (some looked like wind chimes) used to ward off evil or to help women conceive. There is a great deal of witchcraft in Buddhisim to this day. I assure you I have the right country and this was in 1986. I remember it very well as I am not incapacitated and I am not incapacitated now!
The problem I have with your nurses story is that Tibet has been ruled by China for years, and the Buddhist monks there have been suppressed and even imprisoned for most of their lifetimes.
Any misbehavior of the type she describes would be quickly reported to and punished by the authorities. The Chinese communists would make a big point of publicizing it too, to weaken and discredit the Buddhists. I have seen quite a few "documentaries" produced by the communists alleging just thie kind of thing you describe, BEFORE the modernizing Chinese came.
As for superstitions in Tibet "to this very day", I have no doubt it's true, and I can say the very same thing about the United States of America, where more people that beleive in astrology than in any other system of belief, including Christianity.