But Hilary eventually puts her foot down, proving to be the stronger of the two, and the m nage falls apart. Rachel Griffiths' Hilary is the core performance. Though Watson has the centerpiece role as the flamboyant musician, it is Griffiths who gives the more subtle and deft performance. Griffiths is Watson's foil. Watson's performance would have appeared excessive and empty without Griffiths as a dramatic voice for the more complex emotions in the movie.
Biographies suffer an inherent difficulty when transposed to film.
The life of a great person is deceptive. Even if the celebrity were absolutely fascinating, that does not mean their life will make a good story. A biography usually contains some combination of grand accomplishments, high emotion, vignettes and anecdotes, but like most anyone else's life, it meanders circuitously, dumbly gathering material but not distilling it. It makes for a better story to base a film on an episode in the person's life, increasing the odds for a stronger plot and clearer premise. In the last part of the film, Jackie is fighting with progressively degenerative multiple sclerosis.