But on the other hand, at least for the seven main books, she does seem to understand the motivation of her characters quite well, so if any important character in the book does somethign that looks strange to you, such as
scifi.stackexchange.com/q/91195/4918 "Why did Amycus Carrow think he could lie to the Dark Lord?" in my case, then it's better to assume that JKR knew what the character was thinking and why she did that action, and she understands it better than you do.