Girl gets into a big school, parties, gets wasted, crashes into this guys car, in which kills his wife and kid. She goes to prison for 4 years, gets out, and decides she wants to go into the janitor/cleaning field of work. She finds the guy whos family she killed, wants to clean his house for him. Falls in love with him, than later when she wins the trip to Earth 2, tells him that she was the one who crashed into him. He gets mad at her, she gives him the ticket to Earth 2 and ends with her walking up her driveway with her "Earth 2 her" standing there.
The whole thing of Earth 2 was never explained, it is pretty much "Another Earth" just there, with the same people, same history and whatnot there. As if it was the same Earth there, going through everything that Earth 1 went through. End story.