Keying someone's car is so low and very costly. It becomes especially pointless when she doesn't know who or why. Don't do this.
When a person is in highschool, they generally live with their parents. TPing a person's house generally means their parents clean it up and again, is pointless if she doesn't know who or why.
Don't do this for the same reasons as above
Egging a car is probably one of the better ideas if you're trying to piss her off. It's time consuming to clean up, but leaves no permanent damage. Again, the best way is if she knows who did it and why. Without this info it could be random for all she knows.