A book of Hiden would not be a terrible idea, although I would much prefer it to be "scrolls"; with the idea that all of the wandering members of her clan had a few scrolls, but none of them had them all. I dislike the doujutsu she has, mostly because there was a large plot revolving Sai, who literally stole doujutsu and could apply a cursed seal to people that would give them diluted versions of kekkei genkai, including doujutsu. I do not feel it would be a good theme to create a hiden doujutsu.