When it became clear that she was in no danger of eluding her shadow, Hermione changed tactics. She spun around in place to head back towards her true destination. The change in direction could force the stalker to cross her path. Clearly anticipating such a move, she didn't see them. It was frustrating to know that she was at their mercy. Sure, she could leave the area with a simple spell, but she had a purpose for being there in the first place. She didn't like it when people got in her way.