I was contemplating this the other day, actually. I do have two fics that are half done where Mal and Fay are teenagers, and I have a few more done that happen pre-series (Fay's birth, Mira telling Harry's she pregnant, Harry breaking down after Mira's death). My only reservation in posting them is that I feel like if I make them older, I can't go back and write when they were younger anymore. Which is kind of silly, I guess. I have been waiting for my 10_prompts approval forever. If I ever get it, I'll probably post some of them to go with the prompts.