If you check your hen's body, does it feel pretty thin in the lower breast area? Can you open your peahen's eyes? Also, is her face swollen under/around her eyes? If you press on that soft area between her eyesand her beak, is there any sign of snot being pushed out her nostril, or the corner of her eye, or does she swallow (post-nasal drip)? Yucky, I know, but important. Also check in her upper mouth for signs of snot/excess mucus. And while you're at it, check to see how fat she is. I am so sorry about your hen. Don't blame yourself. Sometimes these things just show up so quickly, or the signs are so subtle that they are hard to catch.
