My 10 year old daughter Avalon is an avid reader. She stays on top of current trends and manages to find the latest and greatest books. What is really amazing to watch is how she can disappear into another world and consume a book in one afternoon.
I did the same when I was young so I step lightly around her. Offer her snacks and water regularly. Wait patiently for her to emerge from whatever adventure she has been on. It is an incredible thing to love a story so much it feels real.