"She's trying to make the most of what's left and yeah she kind of makes this, thinks of things she wants to do, but at the same time through the experience realises that some things become important and some things don't matter anymore, and coming to terms with everything and so yeah it was definitely a very complex character but it's been one of the most fun times I have ever had making a film."
Fanning's love interest in the film is played by Jeremy Irvine.
Irvine was plucked from obscurity by Steven Spielberg for War Horse the movie.
He says Now is Good offers laughs, despite its sombre subject.
(SOUNDBITE) Actor, Jeremy Irvine, saying (English):
"She uses it as an excuse to do all the things she wanted to do. So she goes crazy and does all this stuff and gets herself in these situations which are actually very funny and I think that's why I chose the movie, you know, yeah."
Now Is Good is released in cinemas in the United Kingdom on September 19.