Tell Us Your Secret

This one made a big impression on me when I read it as a teenager. First, because it was about teenage writers and there was a lot of juicy material about what makes someone a good writer. Secondly, the female main character was Jewish and descended from Holocaust survivors. She spurns the attention of the male main character because he's not Jewish and she doesn't want to "start something she can't finish." I thought that was utterly bananas but I couldn't articulate why. Add some spooky thriller material and a character who is lying about who she is, and I was fully invested. Unfortunately I soon forgot the title and author, but after years of thinking about it, I was able to track it down and re-read it.