Although at the beginning and end of the film, the actress does portray some aspects of autism well, unfortunately, the remainder of the film portrays autism inaccurately. It is said about the character who has autism that 'there is a person under there somewhere', suggesting that those on the autism spectrum are not people and equal to those who are neurotypical. In the film, the character is temporarily 'cured' of their autism, which is not possible, and some people on the spectrum may find this offensive, as their autism is part of who they are and has a lot of positive aspects. The characters autism appears to completely disappear, and then reappear at the end of the film. Autism is a lifelong developmental disability, so it affects the person for their whole life, in their communication, social interaction and flexibility of thinking, often accompanied by sensory issues. The person can develop their skills in these areas, but through teaching and learning coping mechanisms, there will still always be the underlying areas of difficulty. Despite these difficulties, there are some people on the spectrum who are able to have careers and function in their everyday lives - some think that people like Mozart and Einstein, and Bill Gates, were/are on the spectrum.
For a more accurate portrayal of autism, films like 'Snow Cake' 'Mozart & the whale' 'After Thomas' and 'My name is Khan' are fantastic. The National Autistic Society website has lots of information about autism for those who are interested.