What are you feeding her? How MUCH does she eat and drink? Is the Tylan mixed in her water or injected? The nutri drench should make a quick difference. Are ALL of her poops like that? How long has she been so lethargic? How old is she? Is she inside and being kept warm?
Since you've had her on antibiotics for so long, I'd get some yogurt in her. Plain, unsweetened yogurt with several kinds of flora if you can get it. You called her "little" is she a bantam or a small large fowl or just that she's smaller than you? I ask because it will make a difference in how much yogurt you give her. If she's a bantam and she's never had it before, I'd just give her a teaspoon. If she eats it, wait a while and give her some more, it depends on how speedy her digestion is right now.
Let us know what she's eating and drinking and how much.