Since she's under eighteen and untrained her medical duties are obviously limited, but Hermione assists in basic things like preparing vaccinations for the nurse to inject. She's thankful for the task; without it, she knows she'd become consumed by thoughts of the boy in the waiting room. Who was he? He obviously has some sort of magical power. He disappeared the same way the devil did last night. Why was he here? Is Lucius Malfoy having her followed? The boy's resemblance to the devil is uncanny: she won't accept that there's no connection between them.