Is she very submissive to you? It could be she sees you as different than others. In her mind you're a strong alpha who is treated differently than the average human she can play with?
I notice something like that with a rott/pit mix I've been caring for recently. It seems like he has a respect (deference) for me that he didn't have when we met. I find he opens up when I lay on the floor and play with him (so he's the same or higher level than me). After we play (and we're sitting up) he'll want to put his head under my head, like an act of submission again.
That just developed from him bonding with me, not any dominance on my part. He came from a history of unstable living arrangements, isolation, etc. So, I think he just values what he's been getting from me, and developed a deference like that.
Also, I notice he looks at me when visitors play with him, etc. He'll get into it, then look to me as if maybe he shouldn't be doing that. I've never discouraged him from playing. It seems to be a natural deference. (What you described reminded me of that.).
If your rescued girl put you on a pedestal, you could try doing what I do and lay prone on the floor and play tug, etc., so she feels invited to be at your level (actually has no other choice to be). With the typical puppy we have to work (be patient) as they learn their place lower than us. But, dogs suffered abandonment need encouragement to be a little higher than they've learned to be?