J.C.
OMG she is only 6. My 12 year old does that still although my 7 year old has never done that. Just different personalities.
Sounds like she has too much stuff to manage. Perhaps her room needs to be decluttered.
I put bins under my daughters's bed so stuff can no longer accumulate there. The thing that seemed to be most effective though was to tell her she has 15 minutes to clean her room (depending on how messy it was) then go in with a bag and clean up any messes I saw. She then would have to earn back whatever was in the bag by doing a chore. I stopped doing this when she was about 10 yrs old though and finally at almost 13 she can clean her room independently.