I'm sorry to hear she's not improving very much.   How is her overall behavior - is she walking about some, eating/drinking?  Can she interact with her flock any?
Possible that she may have Lash Material accumulating in the abdomen.
You're feeling movement with your hand under her, hard to know, you may have been feeling the digestive system or even the gizzard going through the paces.
I agree, a comb becoming dull can be a sign of decline.  I've seen it in my hens that have had reproductive problems.
While soaking is sometimes soothing when a hen is feeling poorly, it can be stressful for some and push them over the edge.  If she had a bad turn during her spa time, then I'd hold off on doing that.  If she gets really messy on her bum, then just a washing of the area may be sufficient. 
 Oh dear

   The best thing I can tell you is go by what she is doing.  If she's able to rally and fight, give her more time.
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