Sick Hen - Tube Fed Twice- Crop doesn't seem to fill.

Thelma has been sick before. So tube fed yesterday once and today twice...both times today 2 ounces. She is very thin. So the issue is that her crop doesn't fill up. The has white around vent, will only eat a bit of tomato. Gave warm bath. Checked her vent for egg...didn't feel anything. Head, tail drooping. Poop was green...now a bit of brown. Tube food is: organic plain yogurt, bit of her chicken food, put in a bit of egg and spinach, apple cider vinegar...bit of soft dog food, bit of Vit C powder. I can't get the baby bird food people recommend...so have to put something together. Hummm....Shouldn't I be feeling 'something' in her crop when giving 2 ounces? Thank you!