isn't it odd? her sister is a great layer (although her eggs aren't huge yet, more medium-sized, but a beautiful pearly white) -- and i'll be interested to see how the female chicks i've hatched this spring, who are from her eggs crossed with a cockerel that came for your flock's eggs, will lay! i'm pretty sure i've hatched 8 girls and 4 boys, which is a nice ratio...
the one that doesn't lay also has the wrong color eyes & an "incorrect" comb, so no great loss in not having her as breeding stock -- and I don't feel right selling her to someone, since she's never laid ANY eggs and shows no sign of doing so. the cockerel doesn't even seem all that interested in mating with her, which is part of my guessing that she's of indeterminate gender rather than fully female -- very odd.