Hermione didn't want to intrude on Luna's time with her father. Her intent for the visit had been to support her friend. She had done that and could continue to do so in ways that were more practical than simply sitting there taking up space. She actually felt horrible that Luna was waiting on her father rather than Hermione doing it for her. Still, she understood that this was the first time in a few days that things were back to what had become normal for her friend. Therefore, she sat back and silently watched as she finished off her butter beer.
"I'm happy to oblige either way," Hermione stood and walked over to where Luna sat. "Just let me know what you need. I'm going to head back to my flat." She leaned down and gave Luna a quick hug. "Mr. Lovegood, take care and don't let Luna overwork herself." She knew that her friend would bend over backwards to take care of her father at the risk of letting herself go. Something Hermione needed to be certain she didn't allow Luna to spiral too far into.