Watch Charlotte Wilkins' report from Crawley:
The 12 year old sister of a young boy with Autism has written a book which will be sent to every primary school in the country - to help children and teachers understand what it's like to live with the condition.
Sienna Manuel hopes the story will change people's perceptions and encourage children to be kind to one another. The book was launched at a special event in Crawley.
Charlotte Wilkins spoke to Sienna and John Caudwell.