Hmm. That's a normal soft shelled egg, so I'm not sure. If she's laying she's not likely to be eggbound.
At this point it's out of my knowledge range and I'd suggest a vet. Maybe @casportpony or one of the other members with more health care experience can help you.
At this point it's out of my knowledge range and I'd suggest a vet. Maybe @casportpony or one of the other members with more health care experience can help you.