Lucky you with all those girls!
The hen with the white throat patch has some kind of gene that causes white, probably a pied gene, or possibly a white gene. But does not have two white genes (otherwise she would be white). She could be a dark pied, having two pied genes, or split pied, just having one pied gene.
I'm guessing what @KsKingBee noticed was the same thing I noticed, the white patch hen is lighter colored than the other birds. Neither white genes nor pied genes cause an overall lightening of the bird's color like that -- pied causes areas of white, and white causes an entirely white bird. But neither gene causes feather lightening (dilution) of the color.
White eye genes CAN cause lightening of color, but I'm not aware that a white eye gene will ever cause a white throat patch -- maybe someone else knows?
So I think what he is suggesting is that the white patch hen may have both some white or pied gene causing the white throat patch, AND a white eye gene (or two) causing the dilution of the hen's body color? It's hard to tell at this point, but interesting if that's what's going on with her