Megan Atwood 
Twin Dangers [PDF ebook] 

Emma knows that Sophie is dying for the chance to "dance a pas de deux"with her big crush, Trey. Twin sisters know everything about each other. So when Emma secretly hooks up with Trey herself, Sophie feels twice as betrayed. While Sophie might be upset, she’s not angry enough to send her sister death threats. Even so, when menacing notes reach Emma, Sophie’s the top suspect. Will Sophie clear her name and save her twin? Or will one of the Dario Quincy Academy’s dark secrets destroy them both?