DD is 9.
She has a room of her own & it's lovely, she has enough storage units, a large wardrobe and two sets of drawers.. ie: she has no need to pile evrything on top of her desk and to throw dirty washing in a toy box when there is a wash bask oin her room too!
So, the bedroom was last painted when we moved into this house, about 6 years ago - it's pink with pink curtains and fairy theme, she says it's babyish.
Together we chose some lovely covers and curtains, cushions and lamp shades from Next (I think it's English Rose or something with roses on) and I told her if she could prove to me she could keep her room tidy for 3 weeks we would get it painted and the new covers on.
Long story short is I now have the covers since AUGUST and she has not managed to keep her room tidy AT ALL, never mind of the crappy three weeks.
I did a hugh clear out of stuff, leaving only the stuff she plays with and her massive collection of books, but she leaves books everywhere, there are 3 in the bathroom as we speak and another 2 lying on the mat here in the livingroom....
I don't forget what it's like to be 9 - I shared a room with 4 sisters and had to have all my stuff in its place - but DH is a through other so and so, so doesn't show her an example.
Anyway, my sister visited the other day and said she couldnt wait to see dd's room as she had heard she got lovely new covers etc.... dd then told her mummy said she wasn't allowed it done :( and the stuff had to stay in the cupboard :(
I could have throttled her 
and explained to sister that dd doesn't care enough about her room to have it tidied and I wasn't going to pay to have it decorated and all new stuff in it, to watch it being trashed again.
Sis said I was being a cow and that if I decorated the room, then dd would want to keep it tidy cos it would be pretty...
WWYD? She doesn't have the pressure of putting clothes away or anything, me or dh does that, well, obsiously if she is wearing clothes that are clean I expect them to be hung up, but we put away her clean laundry.
AIBU to not want to decorate it until she can prove she cares enough to keep it tidy?
Am prepared to be told AIBU.