I have some silver pencilled birds, but they do not look like this exactly. It actually looks more like my Silver Pencilled Rock x Black Easter Egger...I was wondering if that's what silver penciling would look like at this age. I've never had a penciled, and really don't see many pics of them here as they're just not that common. But I have to say that was my first thought. Truthfully, it's probably a mixed breed, but it does look female. Try to find her owner first, then if you decide to keep her get her some company. She could eat starter or grower at this point, and fresh water.
Here is a 4 week old Pencilled Rock. The camera was washing out the pigment in their legs. They are yellow.
Here is a male. You can kind of see the yellow here in the legs. This is why I hate using flash..