lately one of my chickens has been laying eggs with a little bit of blood on the outside of them.is this normal or is she having big troubles laying?

It happens and everything is probably okay unless it is a lot of blood. I get small blood streaks from time to time, particularly with new layers. But you might keep an eye out for a prolapse because it means there was a little bit of trouble passing the egg. I don't worry about it if it is a small streak of blood but anything more and I check vents and just try to watch out for prolapse problems. If the eggs with blood are especially large, you really want to keep a close eye on the situation.

Susie

What kind of chicken is she? Pullets will do it occasionally, and every hen does it every so often. I had some Sebrights that almost always had blood on their eggs. The eggs were so big, I don't know how they layed them. The bird weight 13 oz and the eggs weighed 1 oz. Compared to a buff Orpington hen that weighed 150 oz and only layed an egg that weighed 2 oz!