Haha turn it into a joke and be a **** about it. Say sh!t like "woah woah there missy...being my facebook friend is an extremely exclusive club and you have to earn your membership to it. You must first pass a 100 question written examination as well as achieve at least a 90% score on a practical exam." Just mess with her and dont take it seriously as an issue..because it isnt. Keep your frame: that accepting or rejecting her stupid little friend request is not even worth getting worked up over or arguing about. She dont like it, she can take a hike.
Personally, i dont let myself be tagged in any photos except a few select ones (like 4 or 5) that make me look good. Example: one of me with my closest friends, one of me accepting an award on stage, a few nice shots my roommate took with his DSLR, etc. One of the best things i did was created a new profile and only let myself become tagged in a few select photos. Besides, most people look like pathetic chodes when you creep on their photos from 6 years ago when they were all skinny and pimply and didnt dress well, etc. Become an idea, not a person...for all intents and purposes you exist as the badass dude you have become today and theres no need for the public to see the pathetic person you used to be. Delete that ****. You can leave a select few with girls you hangout with to stimulate a bit of jealousy, but obviously delete the very incriminating ones such as you making out with girls, etc. Keep it classy and "accidental"