Get yourself one of those window envelopes. The kind that have a clear cellophane window for the return address. On a sheet of paper, type out the return address of a local hospital, but be sure to include "Sexually Transmitted Disease Unit" on the line above the street address.
Type her name and the school's mailing address on the front of the envelope.
If you use a nice, cheap envelope...not one of those security envelopes...you'll be able to clearly read the word "POSITIVE" that you've typed on the contents of the envelope as well.
If you really want to be mean...call a vaccuum cleaner company like Kirby, Rainbow or Electrolux and tell them you're her, and that you're interested in seeing a demo. Set the appointment for 7:00pm so all hell is breaking loose when they show up. ha ha
Since it's the end of the year, and it's not unheard of teachers getting small gifts of appreciation from students, you have the perfect opportunity to get a small bottle of gag perfume (that smells like uh, poop) and wrap it up & leave it on a desk for her.
Got any old sex toys (that don't look like a penis

) that you can leave in her desk? The principal is sure to find them when she goes in search of the marijuana some anonymous tipster claimed to have seen. Hide the toy under the fisting pictures, next to the elbow length rubber gloves. lmfao