It sounds to me like it could be a negative spirit attachment.
She is only in trouble if it possesses her all of the time, outside of meditation.
The first thing I'd do is avoid meditation, which obviously triggers it.
The second thing I'd do is seek someone who can clear the negative spirit attachment.
You usually attract entities that are a vibrational match for you, so she can also work on raising her vibration to attract higher dimensional entities in future.
Erin has an article with suggestions on how to do this:
How To Raise Your Vibration