One of our chickens was poorly just over a week ago. She had a dirty vent and swollen crop and was generally a bit sad and fed up. We kept an eye on her and she perked up after a couple of days and is now absolutely fine. The problem is, we have three chickens who'd been laying really well, but we haven't had three eggs a day since she was poorly. We presume its poorly chicken who isn't laying. Is there anything I should/could do to get her laying again? Thanks.