"Who is her favorite author?"
Translation:Hvem er favorittforfatteren hennes?
I don't think so. One can be a writer without being an author. An author is usually someone who writes books or plays (so they are also a writer). But a writer can be a journalist, or a comedy writer, or a newspaper editor etc etc. They would not normally be considered authors, but they are writers. I think that's the difference between 'skribent' and 'forfatter'.