I could only tell last summer that if I got 4 eggs then everyone laid one and that only happened a few times last year.I've got an 8 yr old Specked Sussex. I don't think she lays anymore, but for the past couple years I couldn't be sure who in that flock laid what.
A friend's wife told him once that wow the hens laid 2 eggs today! Well she forgot to check the day before.
JT