What is this girls intention?

Im in college and I transfered this semester and a girl that i hooked up with previously is also transfering to the same college as me. previous to me transfering we dated and then broke up and it seemed akward for her to talk to me after the break up, so i figuered i give her some time and by the time we transferd we could be friends. now that im in college ive seen her around and waved to her but she ignores me. ethier way she still seems to strive for my attention. today we had a disscution about our point of view and im an outspoken person, so i grabed the mic and spoke in front of 200 hundred people. on the other hand she avoids voiceing her opinion none the less directly after i voiced my opinion she took the stage and voiced her opinion about the next subject. this is completly opposite of her personallity, so why does she feel the need to get my attention when she ignored it when i greated her? is she playing a game? or is she confused? any feedback would be helpfull. thanks.