This is a Welsummer hen I got about 2 months ago and I was told she’s around a year old. Yesterday I noticed she was standing with her wings drooped (it has been 90+ degrees) but also that she looked thin but I was unable to get her. Tonight she looked worse and when the rooster jumped on her she fell down and did not get back up. I was able to get her then and she’s thin, her legs are not strong (she hasn’t tried to stand since catching her) and her wings are splayed out. She’s laying down and her breathing is very raspy sounding. Her comb is still healing and feathers still coming in from being over bred at her last home (she came from a place with 65 birds that were mostly roosters). The other birds in her coop are not displaying any symptoms that I could see. Any thoughts on what this could be?