What should I do with that kid (1st post got removed)

So me and an old friend of mine got in a huge argument, my "friend" faked being my friend for a year, bullied my art and allat shi, and still managed to make herself the victim and told all our mutual friends that I "abused" her. I don't care about all this but I genuinely want to get my revenge but if I do the same thing that she did to me I'll harm her way more than she did to me, I wanna get my revenge but I want it to be a little bit harmless and anonymous. Do you have any ideas on how do I troll her and get revenge on her?