For one thing, she had nowhere to sleep. The timing was all wrong. She was on bad terms with everyone who held even the smallest amount of affection for her. She couldn't sleep in her dormitory or the Common Room, obviously, and now she couldn't stay in the Hog's Head. She'd briefly entertained the idea of staying with the Slytherins, given the story Remus had fed Sirius, but without the protection of her magic she couldn't be sure she wouldn't be killed in her sleep. A Gryffindor in the Snake pit? Unthinkable.