My BA's are 4 years old and they are still laying quite strong. Some of them are still laying daily. Others 5 eggs a week. Each breed is different. I still think it has something to do with mourning over her best buddy. Just because she laid a couple eggs a couple days later doesn't mean anything. The bird can take days to get deep enough emotionally to stop laying.
I wrote an article here on whether or not poultry mourn you might take a look at...https://www.backyardchickens.com/a/do-poultry-actually-mourn-over-the-loss-of-a-flock-mate
I wrote an article here on whether or not poultry mourn you might take a look at...https://www.backyardchickens.com/a/do-poultry-actually-mourn-over-the-loss-of-a-flock-mate