This story seems inconsistent. The text looks very strange and unprofessional. The "I have heard that before" seems very odd. It's definitely not her, but someone else who found out that she gave you the boots. Maybe you could Face book her see what's up. Regardless, if you want the boots, I'd wait 30 days and see what this person does. If you don't particularly care for them or wouldn't mind giving back what someone gave you, then tell this person if she comes in person you'll give them to her.

The fact she isn't posting to you directly and just asking for them back tells me she's bluffing and trying to scare you. My guess is nothing happens in 30 days.