This movie left the impression that Travers was happy with the movie. But from reading the Wiki page on the subject, it appears she was still quite pissed. There were no further Mary Poppins movies, for example.
Plus, I found it odd that the movie, at the end, portrayed a heart-felt understanding between Disney and Travers... yet Walt didn't invite her to the premiere? It really felt like they had to have a sugar-sweet ending for the movie, but the reality wasn't anywhere close.