I don't get why people always over analyze these type of things and assume she's making up some bullshit excuse. She may be telling the truth. She has her own life to live and own decisions to make so she's not obliged to react in a way that you want. Finding out her reasons or whether or not she was telling the truth is in fact, irrelevant. Just focus on what you want, and what's happening in front of you. Move on and meet other chicks.
I don't take that kind of stuff personally so I would just meet more chicks and keep talking to her. If you really wanted to have a relationship with her, I assume you liked her as a person, then why not keep her as a friend. Its obvious she likes you as a person as well. But obviously she didn't find you as romantically interesting as you hoped. Oh well, shit happens, and there are tons of other women out there. Who knows, she could be an amazing friend who later hooks you up with her friends.