I did my best to try and find if there was a way to submit a formal ticket for the game, and if there is one, it's hidden pretty well.
I know I'm not the only person with this issue seeing as there is another post in the EE:General forums (http://larian.com/forums/ubbthreads.php?ubb=showflat&Number=573358#Post573358
) and there have been a couple topics with several replies on the steam discussion board.
In a nut shell, it seems that Victoria will have the Language of the Faery book the first time you talk to her; however, after that point in time the book disappears. Being as by the time you first reach Cyseal, most people are not going to have the extra coin to buy the book (or know that they need it) - this leaves most everyone without an essential item for a future quest reward that comes pretty soon after you leave Cyseal.
On my solo, lone wolf playthrough I was smart enough to steal a few things and grab some money before talking to Victoria and managed to secure the book when I first spoke with her. So, the book is definitely in the game and obtainable from her (at least at that point).
A quick fix of some sort would be greatly appreciated since most of us are far enough along now to where we really, really need this book asap. If anyone else has ran into this issue and figured a fix out, please let us know as well! Thanks!