J.M. Barrie was a novelist and playwright who created Peter Pan. He became strong friends with the Llewelyn Davies family at a time when his marriage was in decline. He used to play with their boys and their time spent together became the inspiration for the Peter Pan story. In this regard he seemed a little bit like an odd duck; the story about a boy who didn't want to grow up was written by a man who didn't want to grow up.
The movie Finding Neverland plays loose with the facts because it shows Barrie meeting Sylvia Llewelyn Davis after she was already widowed. In fact, he had been friends with her husband and the entire family prior to that. Later when Sylvia became ill and passed away, her will gave J.M. Barrie shared guardianship of her children. It is not clear how close the relationship was between Barrie and Sylvia, but it is obvious that he had a close connection to the entire Llewelyn Davies family.
Where the movie shines is how it ties Barrie's life to the Peter Pan story. In the film we see enough of the Peter Pan play to get a mild sense of wonderment. One of the final scenes is surreal by intention. The movie soars toward the end because it surprises us. This is a film that tries to touch your heart and succeeds. It certainly touched mine.
However, the details of Barrie's life are just drab enough that you probably would not want to watch them a second time.