Silkie with infected eye (Please Help)

Hello, one of my silkies eye is infected/ injured. Were not exactly sure of its cause. We did take her to the vet who put her on 2 antibiotics and pain meds but he was unsure of its cause too as he does not specialize in poultry.

Her eye is very swollen and has alot of pus inside. When we initially saw her keeping her left eye closed we noticed a small white dot inside.

Ive posted pictures, can someone please tell me what this could be.

Also, she inst eating alot either. I can use a siring. We've been currently feeding her yogurt. but what else can we feed her to ensure that she at least does not loose alot of weight throughout this entire ordeal.