It took three - 13 gallon trash bags (full of trash), one very full, very heavy 55 gallon trash bag (full of garage sale stuff) and almost 10 hours but its D-O-N-E! The girl's room is clean.... for now.
And with purging enough stuff, we were able to create a small reading nook inside the closet which was immediately put to use.
Which room to clean next?
I think I better take care of those Christmas decorations first. My tree is looking a little sad these days.