This discussion may contain spoilers!
I don't know of anybody has read this story but, there's this story I read as a kid about a girl named Jane. She always wore a ribbon around her neck. Even when she got married to her husband, she would never tell him why she always wore that ribbon. Long story short, on her deathbed her husband asked about her ribbon again and she told him to untie it, and once he untied the ribbon, her head fell off.
I'm not sure if Faith is supposed to be this character as I've never read any of the comics, they just seem very similar to me. Also when Bigby asked Faith about what happened, she obviously couldn't tell him because of the whole "my lips are sealed thing" but instead she changed the subject to the ribbon.
It seems odd that she would bring it up for no reason, unless she was trying to hint at something. Also when Bigby found her head, her ribbon was stuffed in her mouth. Anyway, just thought I'd share this because I haven't seen the ribbon being mentioned a lot.