I am 29 and let me tell you what my mother did that changed my tune.

My mother took everything out of my room except my bed, desk, and 5 changes of clothes.  I was old enough at the time to do my own laundry, yet you may opt for Stacey to be required to put her laundry in a clothes hamper.  I got one thing back at a time (radio, clothing, posters...etc.) once I had my room in respectable condition for a full week.  That included clothes kept off the floor, desk in order, and so on.  I didn't get the privlidge of TV back for a while.  If that doesn't hit here where she lives, then I don't know what will.  Set your own time frames.   I was put back into a position where the things I cared about were eventually earned back, then they meant more to me.  I had worked for them.  If I remember correctly, taking care of the house (mopping, vacuuming, dusting) earned me back something I wanted... if my room was clean.  Hope this helps!  God bless.