From the full context, the fictional female character is = the fictional detective in the book J.K Rowling is/was currently writing at the time of the article. The 'female fictional is of an age to be interested in -(Trans gender issues and sexual awakening etc).

So the sentence means the character that J.K Rowling is writing about is presumably in her teens, her sexual awakening years. And the book is also set in the current day in the current transgender environment and the surrounding politics, debates whatever.