Soozy is about 3 years old!
greetings from Melbourne Australia! - Page 2
Looks like she could have "rooster damage," Do you have a rooster(s) running with the flock. They pick their favorites, usually the ones that aren't fast enough to escape, and tend to overbreed them- often destroying feathers on back, at head and neck etc. - besides just running the poor hen ragged. A rooster can handle 10 hens, less than that and they get too much loving.
You can buy- what is called a hen apron for them - to offer some protection and also helps feathers regrow. You may be interested in joining the thread "Australia, six states and one funny little island."
Glad to meet you and Welcome to Backyard chickens.
- "Happy Christmas!"