The damned Healers who were responsible for Hermione's care at St. Mungo's wouldn't release her until they were satisfied that there was no lasting damage to her brain following the latest in a long line of concussions she'd suffered over the years. She argued with them repeatedly, but they wouldn't be budged. Remaining in the hospital was the absolute last place she wanted to to be. But thanks to the fact that she still had some residual pain, they wouldn't release her. There was no estimate of when they thought she would be ready to leave either. Maybe the next day if she continued to rest and take her potions like a good girl.