Have you been looking in my office and my house?
And mine just live in a constant state of moderate disorder...
I have noticed, though, that sometimes people who have organizational issues can only maintain extreme order. It's all or nothing. I think that's because it requires more executive function to create order than to maintain order, and the easiest form of order to maintain is the simplest, where there are very few moving parts. Her desk is a very small, limited, utilitarian field, where everything belongs to the same large category, and the subordinate categories are fairly simple (by subject, by class period, by stationery category, etc.). External sources of order are also being constantly imposed on it (i.e., teachers). Her room has many more variables and possible classifications, including lots of things without specific functions, but with emotional value, which makes them challenging to classify.
I know this is an anecdote thread, and not a question thread...but you might try giving her the same standard "bucket" categories, using a handful of consistent labels for them every time, either by function (clothes, toys, schoolwork), or by action you have to take (discard, do, store). Then just start with whatever is closest to you.
