Her story is so bizarre that it suggests mental illness. Remember the hysteria a few years ago about daycare centers where similar stories were told? Many innocent people went to jail on hysterical charges that were untrue or greatly exaggerated.
True satanic abuse is rare. Child abuse is alas common.Sexual abuse is common, But even Freud realized that many of the women who claimed under hypnosis that they were raped were confusing reality with fantasy. Not all memories are accurate.
Crazy people get abused. They are ideal targets because they have little power and no one will believe them.
There is much evidence that the priests chose individuals with little power and few resources.