Complex sentence: Later, at Emma's birthday ball "Emma" (really Savannah) dumps Lance and the real Emma is overjoyed when she hears it because she had been trying to get rid of them ever since they started dating and never had the courage to do so.
Split into simpler sentences: Later, at Emma's birthday ball, "Emma" (really Savannah) dumps Lance. The real Emma is overjoyed when she hears about this, because she had been trying to get rid of them ever since they started dating; however, she had never gotten the courage to do so.