Most Helpful Girl
She's enjoying her freedom. That happens to us sometime. When you broke up you probably made her really sad and she felt really bad about herself. She has since then recovered and feeling better about herself and how things are in her life and she is not willing to risk that again. She doesn't want to get into a big thing about it and doesn't want to blame you.
She probably put a lot of effort and work into making herself feel better. Just let her be. She looks great because she feels better. Obviously, not being in a relationship either with you or maybe anyone is working well for her. Having gone through it I can truly honestly say, if you have any care for her at all let her be. Sorry I can be more positive for you.