The Rage of Sheep — Michelle Cooper

It is 1984 and fifteen-year-old Hester Jones is not having a good year. Her best friend has moved away and, even though Natalie and Lynda are allowing her to hang out with them, Hester's struggling to keep up with her cool new friends. Plus, she has the most embarrassing dad in the world, who is never, ever going to let her go to the birthday bash Natalie's planning. Worst of all, her Science teacher is making her work on a project about evolution with that weird Joshua Mason.
When everything goes wrong and the world stops making sense, Hester has to decide: is it better to be a sheep, or a goat?