Hmmmmm....I just breezed through this thread.
I've never had a a King take any time off from eating. My Kings have always been garbage disposals year round.
I think the warm side temps are actually a bit high. I've actually had better success with cooler hot spots for Kings.
I think Bogertophis had an interesting point in questioning the seller's motives for selling an animal that age. The brumation idea is interesting as well. I've never brumated any of mine, since I don't breed, but it seems to me the current temps are plenty warm enough that if she was cooled already these temps would snap here out of it. But I may be mistaken since I have no hands on experience with brumation.
As for moving her out of quarantine... Did you say there are multiple snakes in the same closet for QT?
Did they all come from the same breeder? Were they all brought home the same day?
This I very important, as QT should be limited to one animal per room at a time. There are exemptions to every rule, but if the came seperately they should be QTd seperately. If they all arrived same day you're probably in the clear, but if you added any at a different time the clock resets to 90 days from latest addition.