I have another broody hen, which I'm happy about. We have a rooster, so she & the other hens should be fertile. I quit picking her eggs up four days ago and she laid her 3rd egg today. Since it's pretty certain that she is going to stay setting, I added one from a flock mate to make 4. I'd like to add a few more, but how many days to I have before the 1st egg and last egg? Can I keep adding until she quits laying? Thanks, as always!