Here's the feather site page, 8th picture down is the amber sex-link.
http://www.feathersite.com/Poultry/CGP/Sex-links/BRKSexLink.html
I am sure know that is exactly what she is.
I bet she's an amber-sexlink!
I got 6 Amber-sex-link roosters out of a assorted straight run bin at tractor supply.
Here's pics of them growing up, they all got those spots as they matured too. Took forever to figure out what they were...