I agree with this. Thanks for stating it well, Shad.Don't feel guilty RC. Firstly the accepted general weight for a hen of a particular breed isn't particularly helpful. All the tribes hens were underweight by USA standards. I think anyone who has seen pictures of them and knows a bit about their history knows they were about as healthy as chickens get.
I mentioned earlier. weight lose/disinterest in commercial feed is hardly covered on any chicken site. There was a rather wise women here when I first joined who spoke with me about this feeding problem with moulting hens but unfortunately she got more ot less driven off the site by the so called experts.
So, it is quite possible that Minnie is having a moult/diet problem. Lots of hens do as you can tell just from this thread. On this thread most of contributors observe their chickens to a rather greater extent than the general BYC population.
If it is a moult/diet problem she will recover and you will know next time.