Um just my two cents. Were you the one that had chickens that were vaccinated for mareks die of mareks? If so, and for anyone who has had vaccinated chickens against a disease that they later died from, isn't that a bit suspicious? Don't you think it's possible the vaccine itself had the mareks...
You got scolded by an egg? Sorry but that's just really funny! I have never been scolded by an egg, but I have now been scolded by chicks. Every time I turn off the light in to the living room(the brooder box is there and it has a glass cover to let light through) they start complaining LOUDLY...
Fine. She is spending most of her time under the brooder, but she got a few pecks of food and a sip of water. The rambunctious older chicks are sorta bullying her.