Take it from a guy who used to be in your shoes. That I don't want to be in a relationship is total BS. Think about it, if some handsome guy who looks like a model, who is loaded, has a nice body asked her if she wanted to be in a relationship, what do u think she would say? Its time to move on. She isn't worth your time and effort you would put into chasing her. You have a much better chance of getting a girl who is interested in you then one who isn't.
No mean No. But! When you are talking to her... ask her the same question again..... if the answer is still no! throw a chasiewbao, bolobao, laiwongbao, hamsupbao , gaylobao , GOTOHELLBAO! look for someone esle that you have an interest in then that way when you walk past her be like "HI have you MET XXXXX"