Join Date: Aug 2009
Location: New South Wales, Australia
Always get a bill of sale - nothing else means much at all.
Call her parents and explain you need a bill of sale, and if you can drop over to get it signed sometime, or if you can meet somewhere, and do it soon. Once its signed then consider addressing this girl - but don't do it first. You have no proof the horse is even yours.
Then talk to her. There is no reason not to be nice or not to be honest. Say you understand she misses her horse, and you're happy to send her monthly updates by email (if you are) but you think its inappropriate for her to continually post on your Facebook and text you, as the horse is yours now and you feel more than capable of making the best decisions for it. If she posts on your Facebook after this de-friend her. If she texts don't respond. She'll get bored soon enough.