Hello everyone. We became backyard chicken keepers one week ago when we welcomed 6 layers of unknown age into our backyard. One hen seemed older than the others (by a description found in our trusty book) and at first was picked on by another hen. She spent the first day hiding in the coop but by the second day was out and about with the rest. This morning, she was hunkered down in the nesting box, not looking well. (Last night she seemed fine.) By 9am she was shaking slightly and closing her eyes off and on. Other hens appeared to be comforting her and she would change location from nesting box to nesting box but never left the coop. At about 11am she hopped down from the box and, according to my 12 year old daughter, started flapping her wings, and then just fell forward and died. It sounded almost like a heart attack. Since I have very little information about her (age, etc.) other than all the chickens on the farm were vaccinated for Marek's, Newcastle and bronchitis.The other chickens all appear well and are laying about 1 egg/day. Thoughts and next steps?