Couple of thoughts....
How old is she? If she were sexually mature, could be off feed from hormone levels?
You said the last meal was a large rat.... Has she defecated it out? No lumps? Not impacted.
Could just be her last meal was so satisfying she's still not hungry.
And of course all the standard stuff, you didn't mention anything about her enclosure, temps or humidity.
-----
Thanks,
Dave Colling

www.rainbows-r-us-reptiles.com
0.1 Wife (WC and still very fiesty)
0.2 kids (CBB, a big part of our selective breeding program)
LOL, to many snakes to list, last count:
26.49 BRB
20.21 BCI
And those are only the breeders 
lots.lots.lots feeder mice and rats 

