When her potions wore off she couldn't stay asleep thanks to the lingering pain. If she allowed herself to think logically, of course it wouldn't be smart for the Healers to let her go. She still had some healing to do and if left on her own, she probably wouldn't rest long enough to satisfy them. Or, perhaps more likely, thanks to the dangers associated with simply being who she was, she might be injured all over again. Whoever it was that attacked her was still out there. There was no reason to believe that they would leave her alone just because they failed the first time.