My observation is as follows; That "upon the motion of her body fits followed...abundantly and very frequently" is that movement from her (the nurse), would cause bouts of affliction to the people accusing her of hurting them/witchcraft. Interpretation of this is, how back then, seeing this in person, live, would cause anyone being accused of the occult and power of people to be believed to do so if any sort of movement from them (witches) cause the accused to act that way. A linkage of sorts, construing her movement to their fits.