Should have had a better ending **SPOILERS**
The movie should have included Diana's trial, or at least a blurb at the end credits stating whether she went to prison or not. I think she probably got off. There were plenty of witnesses to testify to Beth's attack on Diana's car with the telescope, and as the cops pointed out at the end, the 911 call had Beth saying it was all her fault.
But I think if Beth had lived, it would have been a wake-up call for her. No matter how sorry for her I felt, most of the things that happened to her were of her own making. She was an overwhelmed single mom who took such good care of her son that she couldn't take care of herself.
Diana was a real b***h! I hated it when she told Beth "I don't care what's going on, sweetheart, just move the car!" or something like that. Who did Diana think she was, talking down to her that way? I don't blame Beth for trashing Diana's car and I sort of cheered her on!