Authors are not responsible for people misusing fictional work to commit crimes. An author's job is to create and tell stories that people want to read, or explore ideas that make people think. It is not the role of an author to reinforce laws or guard against criminal activity, but to promote conversations about ideas and situations in the world.
Fiction authors are clearly not responsible for the false allegations of their readers. When a book is read by millions, such as "Fifty Shades of Grey," there is always the possibility that one or two unhinged readers will use it to create false allegations (such as the UK girl) or as an excuse to rape (such as Mohammad Hossain is 2015).
People can use anything to commit a crime and create a false narrative. That is not the responsibility of an author of fiction. This girl more than likely has some kind of mental issue and should get help for herself. If she is young and that impressionable, what on earth is she doing reading a book like that. It is very sad.
It is a tragedy that the father had such charges brought against him. Heartbreaking, to say the least. It is not the responsibility of the fiction author to ensure every written word is not taken astray. The problem is that there is an increase in self-serving, hopeless individuals, who will use whatever excuse they can to attempt to get themselves whatever they want.