Katara was a little surprised - and happy - there weren't more people in the clinic.  Somehow she'd expected more after watching some of the people fight Hades, but then most of them were dumb and didn't get anyone to check them out.  She may have been making a mental note of who to scold later.

Millie was very sad to see so many people in the clinic after the events of the weekend. However, she was happy to have been able to help then and now.

When Doogie heard Hades' announcement, he'd thought about leaving, just for a minute. Then he thought about what the people on the island liked to do when they were threatened, and realized that he might be needed here. He was disappointed to find that the clinic already had one patient, but was relieved too, to see that there weren't more.