You’d be surprised. I’ve had chickens who seem fine one day and aren’t the next. They are very good at hiding things 😂
I would wet her food to try to get her to eat it. You could even mix treats in as an incentive. Getting food is probably the most important thing right now.
Do you notice that she refuses to eat or has a hard time pecking straight. I have a similar situation with one of my hens. I give her 1 capsule vitamin E and 1/4 capsule vitamin b conplex a day and it seems to help.