What does it mean when a baby bird chirps all the time.?

I found a baby bird in my yard and I waited to see if the mom would come. She was chirping really loud and after a couple hours waiting I just when and got her. She has feathers but she is really small. I'm guessing shes getting ready to fly. I have chickens and I heard baby birds will eat baby chicken food so I gave her that. I think she ate some of that and she ate the bread in water. She chirps in her sleep as well. When I fed her I tried to feed her again but she kept moving her head so I was guessing she was full but I'm not sure. Should I feed her every time she chirps? She likes the lights out to and my room is really hot because she still needs warmth.