Bella has not prepared anything for Reef's return from the hospital. She hadn't even thought of an excuse for her father and Carter if they found out she was hosting Reef in her apartment. The only thing on her mind is taking care of Reef until he gets better. At least that would ease some of her guilt.
Reef finally agreed to come back to his apartment. Although he initially refused, he lost his voice to Bella and Piper. It's also possible that he realized that staying in the hotel alone wasn't a solution other than maybe he would fall again, or have trouble doing everyday things. The doctor discovers a crack in Reef's knee at the last minute before Bella signs Reef's discharge form, so they put a cast on it. Apparently Reef was hiding the pain in his knee, which he thought was just a bruise. Piper had scolded him, which made Reef grin in embarrassment.