She knew the rules. As long as she remained inside of the village, she wasn't to be harmed by anyone. Not even those who would desire nothing more than to see her dead at their feet. If she followed Dumbledore, she would be at risk of being attacked. But, if she didn't follow him, she wouldn't learn what she desired. She hadn't gotten so far along in life without paying close attention to the suspicious thoughts that crept up on her from time to time. Perhaps, he was luring her over just so he could get rid of her. Not that she would blame him. It was a clever ruse. Maybe Ginny had been lying the day before and there was never any intention to teach her. The dirty work of getting rid of her now that she was inconvenient might have fallen to the elderly wizard for no other reason than he drew the short straw or it was his turn or whatever ridiculous, egalitarian method the Resistance used to decide who did what.