It's not easy to like any of the girls, who only do nice or "good" things when they believe it will accomplish a goal. They're even outright mean to Dahlia, for no particular reason. The teacher is supposed to be quirky and fun, but often seems callous and irresponsible - I get that she's supposedly building life experiences for the girls, but it would help if she didn't make weird pronouncements as she tosses them at some new horrible adventure. She frequently says what a Rapscott girl has to be, and it's usually nonsense.
I think the author is trying too hard to make the book quirky and cute, and the story suffers. Like why would boys and girls with busy parents not get along for very long? They're not socialized at all, so it makes no sense that they decided right away that they dislike the other gender. They shouldn't be able to get along with anyone.