Any ideas?

[Texas Transplant]

She has scaly leg mites, by the way.

ditto

 

[Texas Transplant]

I agree about the Delaware mix....perhaps with a Brahma?

As in Delaware crossed with a Dark Brahma
I used the chicken calculator of both of these color patterns and there's a 50/50 chance for a female to be Black Patterned Silver Partridge/Brown.....which is what this lil' gal is......but, wait! That wouldn't explain her single comb.....hmm a beautiful mix indeed! I would guess some sort of silver Colombian colored bird with a Silver Partridge bird BUT, there's still the leg feathering to account for....throws hands up, idk

 

[RoostersAreAwesome]

She could be a sussex cross or an Orpington cross