Thank you very much for the great description as to what a FBCM should look like, that describes my other hen to a T! I was pretty certain that she wasn't a FBCM, but wasn't sure what she was! She's super sweet and cute!Not a FBCM.
She does not have copper eyes. She has no evidence of copper at the hackles (which often bleeds over to chest, and even back, though back is not standard).
She is not a "French" version as she does not have feathered feet....all down the outside of the leg and outside toe.
Her coloring would be considered blue, for which is a Marans color, but her skin appears to be black. Marans have yellow skin with red combs and wattles...hers appear to be coming in grey/black, including earlobe.
She also has a crest.
I think she is a Silkie mix.