"I think it’s the effects of a lasting spell." The bookkeeper sounds certain. She doesn’t call Hermione crazy, she doesn’t threaten to tell McGonagall or St. Mungos. She sees that Hermione is struggling and is offering her support. She starts rooting around for books, flitting around her shop with experience from working there for likely years. "These are all the books I have about manipulation spells. Warning, there are at least three on the imperius curse so it might get a bit dry."