extremely tiny rhode island red
- Flock Mistress
I am inclined to think she is not going to live, but as long as she is happy and healthy I would let her try. Usually, unthrifty chicks show a variety of problems besides just lack of growth- underweight, poor/lack of feathering, frequent pasty butt, sleeping more than normal. If your chick has none of these then maybe she will surprise you and live a long life.
You might want to start a new post in the Breeds, Genetics, Showing section of the forum. They can probably help you out more over there. This section is more for illnesses and injuries, but it sounds like your little bird doesn't have either one of those going on. She is just...petite. I would be interested in seeing what the folks over in the genetics section have to say on the matter. If you do post over there you may want to include pics in your new post because they are going to ask for some. And send me a link to your new post via PM. I don't get over there much, so I wouldn't be looking for it. I am curious, though.
Good luck with her.