I#m not sure why you are being advised to supplement calcium. There is more than enough calcium in normal layer feed to see them through moult, especially as they usually stop producing eggs at this time and are therefore not using up the calcium in their layer to produce egg shells. Some meat/fish/insect protein will definitely help her..... maybe some cat food once a week to give her a boost. You may find that some of her flock mates will follow suit and moult very soon too, or as others have said they may have discretely moulted.
It does seem odd to us that they moult at this time of year when the weather is getting colder but I have a theory that it enables them to naturally knock down their external parasite population before the winter climate makes dust bathing difficult. Not necessarily saying that your birds have lice or mites but these seasonal strategies are formed by evolution over thousands of years and providing a heat source may actually thwart the purpose, which is to make it too cold for those parasites to survive. Better to provide good quality food so that they can keep themselves warm from inside until their new winter duvet grows in.
It does seem odd to us that they moult at this time of year when the weather is getting colder but I have a theory that it enables them to naturally knock down their external parasite population before the winter climate makes dust bathing difficult. Not necessarily saying that your birds have lice or mites but these seasonal strategies are formed by evolution over thousands of years and providing a heat source may actually thwart the purpose, which is to make it too cold for those parasites to survive. Better to provide good quality food so that they can keep themselves warm from inside until their new winter duvet grows in.
