Do any of you know what movie this is?

It came out around 2006-2008. It was about this tough underprivileged girl who hits a guy with a shovel or beats him up fatally and kills him. The guy's ghost follows her around. Near the end the girl goes into the emergency room where the guy is being held and somehow saves him, sacrificing her own life, while he is dying. The guy says, "(Insert name here) you saved me." At the very end he is flying kites with her younger brother in remembrance of her. The guy and the girl are both high school students and the girl does something to the guy to get expelled or suspended.