I have a scale.

I;ll go ahead and weigh her. She eats, i saw her eating the chick food yesterday. she does't' have a messy bum. just the rooster does. she is a tiny one. she is just very small. much smaller than my other girl. she laid her first egg the other day but hasn't laid one since. she's out in the run where I can see her now. some of the snow has melted and I shoveled it out enough so they can at least get outside a bit now. it isn't a big space, just enough to hop out and look around really. she's been out. she doesn't sit around, she's pecking at the ground etc. when I had one that died before, she just sat there and looked fluffed. I knew something was off with her, that was the one who kept getting cocci over and over. I should have quarantined some chicks that I brought in last year, they brought the cocci and it all started from there

I don't see any signs of cocci now though.
I'll go ahead and try weighing her, but I don't know what her baseline is and she is quite petite. But, I can at least see if she's losing weight further.