"I've offered verious sizes of rats and recently a FT quail. She looked interested in the quail but did not take it. "
Since she has some interest in food, perhaps, but not in the rats you're offering, this makes me think of a tip I give new keepers who get snakes from me that won't eat in their new home: try rats from a different source. Some snakes are funny about the source of the feeder (probably what the rat was fed, what substrate it was on, and the like) and a couple times I've had snakes eating very well for me, but the new keeper couldn't get them to feed on prey from their source; simply getting a rodent from a different vendor worked like a charm.
Trying a prekilled rat might be the ticket, too.
As a relevant aside, I hope you're not offering the refused prey to your other snakes. Not trying to be insulting or something with this, just a friendly mention about pathogen control practice; I kind of assume that a snake that has not yet fed is still in QT anyway.