One Past Midnight by Jessica Shirvington

Every night, at exactly midnight, Sabine switches lives. She's still Sabine, 17 year old girl on the cusp of graduating high school.  However, her families are different, her location is different and her future in both lives is definitely different. Sabine's physical presence crosses over too, so when she breaks her arm falling down in one life, she spends all day trying to figure out how to make a broken arm look like an accident in her second life without throwing herself down the stairs. But when she Shifts at midnight with two functioning arms she knows something has changed. She now believes the opportunity to choose her better life is finally available. Will Sabine make the right decision?

One Past Midnight is a great book that shows it's not always greener on the other side.  Also, I love Shirvington's other series: The Embrace Series.