Why does she fear she might do something bad?

She has fears of this because it is being suggested to her that she is going to lose self-control and do terrible things. This is another way of ramping up inner fear and doubts about her future to keep her off balance. So again, this is a propaganda campaign but it can be very effective because people are sensitive and the mind will not know what is real and what is really just talk. In reality, the spirits have a limited power to manipulate a person. Their greatest effectiveness is achieved through psychological abuse, and in a sensitive caring person it is quite unnerving to receive brutal treatment at the hands of another consciousness. So here again, there is a good fit that dark spirits will carry out a propaganda campaign as they work to manipulate thoughts and feelings and instill corrupted beliefs within a person. And at the same time, will threaten them with suggestions they are losing their mind and will go over the edge, so to speak, and this can become quite terrifying with mounting evidence suggesting it might be true, even if it is all talk.