Having seen it last night. I thought it was a well-crafted film. Though it wasn't original since we all know about drugs and the struggle to recovery. Still, I have to give Maggie Gyllenhaal a lot of credit for showing the struggle of recovery and how she can fall apart. Sherry is a selfish, childish woman who tries to strive for attention, especially from her father and daughter.
The one scene that I didn't like at all was when Maggie sang that f*cking Bangles song. It's not Maggie's singing (though she is a good singer) but the song. The original Bangles version is pretty awful and Maggie's isn't any better.
For the ending, well I think after trying to reconnect with he daughter, Sherry realizes that it's going to take a long, long time for the reconciliation to happen. She did some stupid things, crossed state lines and is likely that she's going to jail. That final scene with her brother (who did a great performance) where she asked him to take of her daughter seemed fulfilling since Sherry can barely take care of herself.
It's a shame the film didn't get a wide theatrical or even a good arthouse release since it never came to Atlanta.