Hi There El and Damo
Is she with a roo" at all, as sometimes if they are an older hen the boys can be a tad brutal on them...
I had a Brown Barnie Hen that was an older hen when she was delivered to me (much to my disgust) but I fell in love with her and her "Fat Albert" ( that thread is on the "Which birds did you love the most in your pens").
She was with us for about 4 years and then she got "pummeld" by a younger rooster and had an injury as a result.
I think they are like us,Once they get older they just can't cope with physical confrontation.
I isolate my girls and my older boys if I think they are getting a tough time and I have the facilities to do that but make sure they have a companion as they may fret...
Restrict her excercise but at the same time don't lock her up so much that she cant move at all..
Good Luck
