Your sense of this is spot on. She has had long-standing spirit attachments and the exalted state created by this substance brought in additional energy and this was noticed and exploited by her onboard attachments to gain an even larger degree of control over the mind and manipulate her more intensely. This has had its ups and downs and is the reason for her current difficulties.
Her dark dream experience was the emergence into conscious awareness of what was going on in the subconscious as a consequence of the onboard spirit meddlers creating quite a drama for her. They manipulate the subconscious mind directly and introduce themes for the subconscious to ruminate about that play off of prior karma. So past hurts, past disappointments, past failures, and past traumatic events will come up as a plot for the dream state and will impulse the host with twists and turns in the plot to make things very unpleasant and even creepy in nature. Keep in mind they are drawing from a vast experience base from corrupting human beings for many thousands of years as individual consciousness. It is not that they are brilliant, it is that they are experienced and they gravitate towards dark thoughts, dark intentions, and dark themes so this is quite natural and a good fit for their energy and a natural product of their thinking. The answer for her is to have a Lightworker Healing Protocol session, not only to remove the darkness present but help to establish a greater level of protection. This cannot be guaranteed but is a beginning at least.