Hermione didn’t want to risk having Ron turn away from her and reject an attempt at smoothing things over and pretending nothing had happened; that would crush her. And she refused to apologise – she hadn’t been in the wrong, he had. Her pride wouldn’t allow it. So she stared at Ron and hoped desperately that he would be okay. That once the mission was over, and she had given him some more time to sulk, everything would go back to normal. They just had to get back to Godric’s Hollow safely.