Not a good book, but no worse than most fantasy out there. A homeless teenager discovers that she has a magical talent for healing. Unfortunately, this makes her a valuable prize to the gangs of her city--and the fae that control them. Unimaginative in every possible way.
Available at Baen's free library here
. But really, if you're looking for elves and healing in the big city, just read John M Ford's The Last Hot Time.