First of all sorry for my weak english .There is a girl in my class who showed me some interest at the beginning. After 3 months ,finally I told her that I like to hang out with her and get to know her better. it was too early to ask a girl out but I'm a shy person and it was really hard for me to flirt with her. She told me that she is with someone right now however, she is not sure what will happen because she hasn't received any news from that person recently. She said time will fix all issues and then she left. Since that time, I have started ignoring her and I'm doing my best to forget about her. She initiates conversation sometimes after the rejection but I replied her short and cold. Do I still need to keep doing this or I should change my way  

I would appreciate if anyone can help me