I'm worried about the floor becomming full of stuff, since it's so deep. I could easily do a closet organizer or an Expedit, but I'd still have 2 feet of floor before the door and I can see her opening the door, dumping something in, and closing the door. This is what I did for a couple years
.
When we only had 2 kids, her room was our guest room and the closet was my office. I had a desk, file cabinet and bookcases in there and it was great! I loved being able to shut the door on it all. But, that should tell you how big it really is.