WTH??!!!

I am very particular about who I accept friend requests from on social sites. My "friends" are people that I grew up with, or attended school with for several years. I do not accept friends of friends, or random people. So i check my email the other day and get a request from someone who is DEFINITELY an EX-friend. Our friendship broke up many years ago with no uncertainty for very specific reasons. Unfortunately we had spent years around each other, but not long enough for her to be a decent human being and good friend to me. I said cool, I'm done with you #die bitch. The problem was having mutual friends I learned to do the social dance and when there were events I made sure that we sat on opposite sides of the room, or she would kindly come early and leave early, or just not show up so that we didn't run into each other at all =). What is this bitch thinking??? No I don't want to be her friend on fb she's no one/nothing to me. At this point I'm debating do I 1]ignore her, or 2]respond with a simple Why? These hoes are hilarious...