[Ironhorse]

Horses were the automobiles of the colonial era. They supplied transportation, food, muscle power, etc. Think of it like she steals a car every night and goes to parties, races, does a little work on the yard and such and then returns it. A coven might race for fun, have a equine beauty pageant, show off their spell's control and power via enhancements to their horses, odd fur patterns, etc.

The victim would wake up tired, with grass tinted morning breath. She may notice her hair still has vestiges of odd fur colors, thistles in her hair, etc. Perhaps some rope burns on her neck or arms. Also, the missing horse in the stable, but all the evidence that a horse is around, droppings, gear, smells, tracks, are all over.