"Ginny was kneeling beside the injured girl now, holding her hand. With a huge effort Harry forced himself on. He thought he saw Ginny look around as he passed, and wondered whether she had sensed someone walking nearby, but he did not speak, and he did not look back." (Rowling, Harry Potter and the Deathly Hallows, 697)
Ginny heard something move behind her and snapped her head around to see who was there, letting go of the crying girl in a moment of panic. Were the Death Eaters back already? The hour wasn't up yet! Her eyes searching the darkness, she found no one. Just as she was about to turn back to the trembling girl, she caught sight of something just above the ground and stifled a shriek. About five feet away, she could see an inch of the bottom of a pair of trainers. Blue trainers. Trainers that she would know anywhere. It took all of her willpower to turn back around. She heard him move away.
"Harry," she let herself whisper.
She knew where he was going: straight toward the Forbidden Forest, right into the clutches of Voldemort. Normally she would be worried that he didn't have a plan; he never had a plan. But she knew, this time, that he did. He was going to die.
She knew he thought he was doing the right thing. She knew he was doing this to save everyone, to save her. That didn't make letting him walk away any easier.
After she helped the injured girl into the Great Hall, she found a secluded alcove and let herself cry.