We were told a few days the posting (by the donor) that they are a year old, and in battery conditions it was normal for that age :-X. We gave two of the four girls to a friend's son as first hens and he is brilliant with them.
Since we have had them, allowing for settling-in time, we are up by six eggs per day. My mind boggles when I see them but they are settled in with the others and just getting the hang of scraps, space and us.