Things to work on: The Window lighting is distracting. Change angle so that the window light comes from your back or from off to a side.
This would also eliminate the shadows from the flash, whcih make this a snapshot quality photo.
Try to use the rule of thirds in your photos. The subject, in this case the girl would have been stronger if she had been moved to the very left of the composition with books filling the rest of the frame.
Yes there are a lot of books. Sorta looks like the subject is in a library rather than a book collector. The lights from the window is distracting. Perhaps a different angle would have been better.