I say bug her. If you ignore her, then she has won her game. Play her game - try to talk to her as much as you possibly can - annoy the **** out of her - eventually she will burst out and scream at you to stay away or something. Then thats the moment you've beat her at her own game. And remember - its a game. She doesn't want you. So don't try to make fancy moves or buy her shit. just try to casually talk to her as if friends would. She'll either explode on you, or start talking to you again as friends. Either way, you win.