Definetly Sick, Not sure why!

[NonnasBabies]

I have a hen that's not acting right. She's either 9 or 14 months old (I have 18 of this breed so I can't tell them apart) Her comb & waddle are very pale and she's just not really active. I find her laying by herself when their free ranging and she gets up on the roost way before she normally would. I've checked her crop it feels fine. I've checked abdomen to see if she's egg bound and I didn't feel anything. She doesn't have any mites, lice, etc. Her vent looks normal. I've searched posts but I can't really find anything!

I'm not sure what other steps to take. Any suggestions would be appreciated!!

Thanks,
Missi