It is probably not wise to breed and hatch eggs from this bird Clawstar. If she was born with this condition, she most very likely will pass down undesirable traits if not the same condition that she has to her offspring.
You can mark baby chicks with felt markers in the head for indentification, using different colors on the heads. Even leg bands work as well. Say...blue is from male X and female Z for example. You will have to keep notes. If you are going for size, you can weigh eggs from breeders and mark them as well before setting. And yes, you will need to cull. You do not want to breed undisireable birds. I kept my unwanted birds in their own quarters so I could tell them all apart as adults.
