It looks like an injury. Could be from trying to get things on the other side of wire, or caught on a feeder or waterer, hard to say. If it's not bothering her I would just leave it alone. It should eventually grow out, though beaks grow slowly and it will take some time. I would just keep an eye on it, make sure cracks don't form, or that it doesn't start to split as it gets closer to the end of the beak. Also try to figure out where it may have happened, watching her as she goes about her day might give clues, to see if you can remedy what is causing it.
My girl, Rocky, got one all of a sudden today. I think it's from the treadle feeder. I put blue Hen Healer on it and will look at it later just to make sure she's good. Doesn't seem to hurt her but it looked like it bled a little. That's why the blue ointment, to prevent pecking. I hope your baby is okay!