For some reason, every character in the series stepped into this particular book and chose to be insufferable. Ashley was at least trying to do things with good intentions, but pretty much everyone else was just awful in one way or another. The main plot with Mary-Kate was riddled with selfishness, and a new character being fed up with it (and with good reason!) only to cave and help in the end. They painted this new girl as a villain when she hadn’t done anything wrong.
The ending was quite wholesome though, so that kept it at a neutral 3.