Jennifer There is a fair amount of language that is used by the main character in her own peculiar way. I would say that it is primarily written from the American perspective as the main character is an American. There are loads of Britishisms and even other languages peppered throughout.
Daz Since neither British nor American are languages neither would be the answer. However, as I guess that you are referring to the use of the English language I will reply that it is written in American English.