I don't know if this has been said already, but I used to do this:
1) Install an REXEC daemon on her win98+ machine. (If she is a ditz, she won't see the icon down in her systray area.
2) Have fun! Important boss meeting with her in her office? Rexec sol.exe to kick up solataire, and then walk by saying "Oh, you criticize me but I can see you have time to play solataire!". Or write a batch file that brings up her browser and routes it to a porn site. Now that will learn her! The sky is the limit!