Waaaaay back in the day, I wrote about half of a Legomance, the original sin of LotR fanfiction. To my credit, however...
1. It wasn't a Tenth Walker story, as she met up with the Fellowship in Lothlorien,
2. It wasn't an "OMG sad abused girl falls into Middle-earth SQUEEEEEEEEE" sort of story, and
3. The story was never posted anywhere and has since been deleted from my computer.