I have a whole flock of hens who will eat their own eggs, but I've always been able to stop them. I give them calcium (oyster shells), which thickens the eggshell. They usually give up on trying to peck through the shell when I do that. Also, I've found that they like to push the hay in their nesting boxes to the side so that the bare wood on the bottom is what they lay their eggs on. This cracks the egg so it looks interesting enough to eat. If I take care of these main things when they turn up, the hens usually stop eating their eggs. It's an ongoing management thing; we only have the chickens for eggs and pets, so it hasn't really been that big of a deal for us. Hope your hen stops her egg-eating!
