Should I accept a friend request from an old school mate (mate used very loosely) on Facebook?

Should I accept a girl, I shall call her A, that I went to school with to my friends list on Facebook? I now have nothing against A, but when we were at high school together I was a bully to her, no one else just her. I'm not quite sure why, she just irritated me. I know what I did was wrong, we both live in a big city, A being further out than me and I doubt apart from the odd school reunion we will ever meet again. I don't ever plan to talk to her on facebook, personally I think A is just trying to build up her friends list. But why would she want to add someone who was clearly horrible to her and made her years at high school uncomfortable? I know I wouldn't go out of my way to do so, but she has. I don't want to cause her anymore torment but I'm not sure seeing my picture on her friends list is going to productive for her. So my question to an impartial audience is do I add her? Thanks