That upright stance makes me think a gamebird of some kind. I had a beautiful OEGB that looked a lot like her. Eventually, she ended up being marked like a Delaware, with black wings and tail and black around her neck. She has the dark legs, too. For the longest, I thought she was a Silver Sebright, til she got her final feathers in. The darker ones on the body came in solid white. I have a feeling she's not in her final color yet.
Good luck!
Shelly
Good luck!
Shelly