Do not abandon hope she will produce full sized eggs soon. I have several Barred Rocks that do the same thing. They almost always lay a medium to large brown egg but now and then it is just barely the size of my thumb nail. I think they do in on purpose just to make me think someone is just starting to lay.I have a Barred rock that lays me an egg every day almost. She took Sunday off. That must have been her day of rest. She just started laying and gives me small brown eggs. Two of them together would make a good egg. I guess they start out that way. I have New Hamps that are 22 weeks and haven't laid yet.