I would make the food a bit more wet than a paste, see if she can eat it on her own.
Work on hydration and getting the vitamins into her.
Vitamin Dosing is 400IU Vitamin E and 1/4 tablet B-Complex daily.
The vent is pasting over, she needs hydration. Clean the vent gently with a bit of warm running water. Dry her very well, use a hair dryer to get the fluff dry if needed.
Apply a dab of triple antibiotic ointment, Bacitracin or coconut oil on the vent tissue to help heal and keep the poop from sticking so much.
Make sure she's not overheating. What's the brooder temp on the warm side and on the cold side? Food and water should be on the cool side of the brooder. The whole brooder does not need to be hot or extremely warm. Only one place in the brooder needs to be warm.