First of all, thanks everyone for your responses. They were super helpful.

So per my previous post- DH said to me "I didn't offer SD to use the treadmill, I said it wasn't a toy" after he just boastedthat he had taken SD9 down to my office to see it and specifically offered it to her as something she could use at her leisure...

Well she said last night in front of both of us -"I didn't get to go to gymnastics today, so I think I'll go downstairs and run a mile on the treadmill!" To which I just looked at DH like, "you dumbass" and waited for him to say, that's not appropriate or something, and correct the situation, which he did not. But he finally sheepishly said, "um, well, SD maybe you can just run around the house a little if you need to burn off some energy." Guess I'm going to have to spell out some new rules about this. But so far she hasn't touched it. She hates being alone so I can't imagine this happening anytime soon unless he goes down with her and holds her hand.

This morning though, I was doing work email and drinking coffee in the kitchen, and I saw her sneak by me and go into our bedroom while DH and the other kids were upstairs. I waited a minute to see if she'd come out (like maybe DH sent her in there to get something for him) but she didn't. So I walked into the bedroom and started brushing my teeth- no sign of her in the bedroom or bathroom- walked into the closet and found her sitting on the floor putting on my heels to go with her sundress. Um, NO!

So I (nicely) gave her a lecture about personal space, privacy and sneaking around, and told her she is not to come in our room without our permission, that these aren't her clothes/things to play with, that we don't take other people's things without asking- this isn't her closet or her room- when in fact she's the ONLY person in the house who actually has her own room. I even went on to explain that she has her own room so she has some privacy and I'm trying to keep the little ones from getting into her stuff, and teach them to respect other people's things, but how can I do that when she herself doesn't abide by those rules (??!!!) So she tried not to cry and ran upstairs to her room but never apologized or took any responsibility (she never does.)

I told DH how this all went, just in case today is the day I forever become the Wicked Stepmother. He laughed it off and said "oh, okay" - but I don't really think he gets it. He's fine with her being an equal in our home. UGH.

Anyway, thanks to all of you who nudged me in the direction of standing up for my adult rights and privacy in my home. I have no problem demanding respect from my own kids but with SD everything feels like walking on eggshells.