Hello,
Well I don't know how sick of it you are, but if you are at your wits end with it, here is what we did with my teenage son.
First I gave him a warning. I said, if your room doesn't get cleaned by tomarow then when you're at school i'm going to clean it. He didn't clean it, so I went in while he was gone and heres what I did.
I took large trash bags and I bagged up clothes in one bag. If he wanted those clothes back he could take them to the laundry mat and wash them himself. I have a washer and dryer but waiting in a laundry mat was more of a lesson for him.
Then anything that I bought him that was expensive went in a bag and was placed in storage. In his case these were things like baseball card collection, trophys, and sports equipment. I also took things like his stereo, tv, phone, computer, whatever.
Then anything else that was on the ground no matter what it was went into the trash.
When he got home he was of course extrememly mad but, he was told that was what would happen. Because I went through with it, he now beleives me whenever I say it will happen again if his room doesn't stay clean. His room stays pretty clean most of the time.
He lost out on some things that went in the trash but, that was the payment for disrespecting my house and my rules. Everything else that went into storage he got back one piece at a time as his room stayed clean.
The clothes, he got back when he went and washed them.
As for stealing your socks, that's funny cause our son steals my husbands socks all the time. His shirts too. It drives us crazy. What we started doing is making him take them off whenever we noticed it, no matter where we are. This way he is imbarassed by it too. We've also taken things from his room in return such as his favorite shirt, so he can see what it's like. This seems to be working.
Well good luck! Hang in there. She'll appreciate you for the dicipline later in life.