if he is on the "pills" can't you just add her to your flock? He probably doesn't even miss her or ask him for her? Personally, I would add her and I am sure he won't ever ask about her. It is one of those, do what is best for the chicken? Poor girl, she really needs the company. Has she been...
chickens are very social animals and she is obviously very lonely.
I would put some straw inside and the fake egg is a very good lure for her. She really wants company. great that you are so caring to help her out. Plus, you can have some fresh eggs!