My chick is sick, what can i do?

[polloamante]

My new chicks came on wedsday and this morning i have one that appears to be sick, all others are fine and peeping and healthy and even this one looked healthy yesterday and the previous days. Her eyes are shut, but not crusted, there was a small amount of bedding in her eye but i pulled it out and cleared her eye, she is lathargic and can barely stand then goes to sleep, her vent was almost sealed this morning so i cleaned it and put her in isloation, i put a little vinegar in her water and gave her food but she hasnt touched it in the isolation box. Ive been clearing her vent and eyes , i would really love some help, i really dont want to see her pass.