-------------------------------------I agree that blood on eggs is not normal but it happens occasionally, especially if the egg happens to be a bit larger than an egg that the bird would normally lay and a capillary broke as the egg was expelled. Egg size is not something that can be controlled by diet but having sufficient calcium, phosphorous and Vit D in the diet will help her lay her eggs without problems
If the shell was not totally hard or it was thin shelled this would cause some blood to be on an egg, especially with first time layers. When the shell is thin the surface of the egg in the uterus is chalky and will adhere the tissue to the surface. And as the egg expelled the area of the oviduct that was slightly ahherred may have bled a little.