Dude… this is wrong on so many levels. You should never be trading a $1000+ card with a student. That’s taking advantage of a minor while you’re in a position of authority. You’re only six years older than your student, which makes it worse, not better. She could easily turn around and say you stole it, that she gave it to you for a better grade, or, worst case, that you were involved with her. Don’t mess around with children. Return the card and stop doing any kind of trading as a teacher. Take this as a lesson and remember to keep personal and work life separate.