We also got one room cleared out and made it into a nice playroom for her little guy. I'm actually really glad for that, he has a space he can get into and relax in.
I don't know if she will keep it up or not, she actually didn't really want us to clean but we basically insisted and did it anyway...I offered to do laundry since it honestly is just thrown in piles all over the house. I figured if were cleaning we should have laundry going too, but she said no, that she would do it. I was literally tripping over dirty underwear to get from one room to the next...
So I think she is inspired, for now anyway. She said she would like some more help, but I told her that she and her DH need to do some purging first, since I am not going to decide what needs to be thrown out and kept. Once she gets the next room cleared out a bit, we will likely go back and tackle some more.
Thanks so much everyone for your replies and suggestions!