I agree with MySweetChickens - If she has access to plenty of oyster shell, and you provide good nutrition, she will more than likely resume laying normal eggs soon.
It is not unusual to get an 'odd' egg - Shell-less, thin shelled, no yolk, double yolk, uneven and rough surfaces - I even saw pictures of an egg INSIDE another egg once! It's all a part of the surprise of egg collecting each morning!