I have an older copper Maran hen called tatsie, who is now perhaps 3 years old and is head of the flock. She was bitten badly by a dog some months ago but has bounced back into health since. For the last 2 weeks her eggs have been soft shelled. Should I cull her? She lays well and eats layers pellets but the eggs are so soft they are just like paper and mess the nest box. What to do?!